Technical standards for the interpretation and reporting of constitutional copy-number variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics (ACMG) and the Clinical Genome Resource (ClinGen)

Fetal congenital talipes equinovarus: genomic abnormalities and obstetric follow-up results

OBJECTIVE

The etiology of congenital talipes equinovarus (CTEV) is unknown, and the relationship between chromosome microdeletion/microduplication and fetal CTEV is rarely reported. In this study, we retrospectively analyzed fetal CTEV to explore the relationship among the CTEV phenotype, chromosome microdeletion/microduplication, and obstetric outcomes.

METHODS

Chromosome karyotype analysis and single nucleotide polymorphism (SNP) array were performed for the 68 fetuses with CTEV.

RESULTS

An SNP array was performed for 68 fetuses with CTEV; pathogenic copy number variations (CNVs) were detected in eight cases (11.8%, 8/68). In addition to one case consistent with karyotype analysis, the SNP array revealed seven additional pathogenic CNVs, including three with 22q11.21 microdeletions, two with 17p12p11.2 microduplications, one with 15q11.2 microdeletions, and one with 7q11.23 microduplications. Of the seven cases carrying pathogenic CNVs, three were tested for family genetics; of these, one was de novo, and two were inherited from either the father or mother. In total, 68 fetuses with CTEV were initially identified, of which 66 cases successfully followed-up. Of these, 9 were terminated, 2 died in utero, and 55 were live births. In 9 cases, no clinical manifestations of CTEV were found at birth; the false-positive rate of prenatal ultrasound CTEVdiagnosis was thus 13.6% (9/66).

CONCLUSION

CTEV was associated with chromosome microdeletion/microduplication, the most common of which was 22q11.21 microdeletion, followed by 17p12p11.2 microduplication. Thus, further genomic detection is recommended for fetuses with CTEV showing no abnormalities on conventional karyotype analysis.

Prenatal diagnosis of chromosomal aberrations by chromosomal microarray analysis and pregnancy outcomes of fetuses with polyhydramnios

OBJECTIVES

To explore the prenatal clinical utility of chromosome microarray analysis (CMA) for polyhydramnios and evaluate the short and long-term prognosis of fetuses with polyhydramnios.

METHODS

A total of 600 singleton pregnancies with persistent polyhydramnios from 2014 to 2020 were retrospectively enrolled in this study. All cases received amniocentesis and were subjected to CMA results. All cases were categorized into two groups: isolated polyhydramnios and non-isolated polyhydramnios [with soft marker(s) or with sonographic structural anomalies]. All fetuses were followed up from 6 months to five years after amniocentesis to acquire short and long-term prognosis.

RESULTS

The detection rates of either aneuploidy or pathogenic copy number variants in fetuses with non-isolated polyhydramnios were significantly higher than those with isolated polyhydramnios (5.0 vs. 1.5%, p = 0.0243; 3.6 vs. 0.8%, p = 0.0288). The detection rate of total chromosomal abnormalities in the structural abnormality group was significantly higher than that in the isolated group (10.0 vs. 2.3%, p = 0.0003). In the CMA-negative cases, the incidence of termination of pregnancy, neonatal and childhood death, and non-neurodevelopmental disorders in fetuses combined with structural anomalies was significantly higher than that in fetuses with isolated polyhydramnios (p < 0.05). We did not observe any difference in the prognosis between the isolated group and the combined group of ultrasound soft markers. In addition, the risk of postnatal neurodevelopmental disorders was also consistent among the three groups (1.6 vs. 1.3 vs. 1.8%).

CONCLUSION

For low-risk pregnancies, invasive prenatal diagnosis of isolated polyhydramnios might be unnecessary. CMA should be considered for fetuses with structural anomalies. In CMA-negative cases, the prognosis of fetuses with isolated polyhydramnios was good, and polyhydramnios itself did not increase the risk of postnatal neurological development disorders. The worse prognosis mainly depends on the combination of polyhydramnios with structural abnormalities.

Prenatal risk assessment of Xp21.1 duplication involving the DMD gene by optical genome mapping

Structural variants (SVs) of unknown significance are great challenges for prenatal risk assessment, especially when involving dose-sensitive genes such as DMD The pathogenicities of 5'-terminal DMD duplications in the database remain controversial. Four prenatal cases with Xp21.1 duplications were identified by routine prenatal genomic testing, encompassing the 5'-UTR to exons 1-2 in family 1 and family 2, and to exons 1-9 in family 3. The duplication in family 4 was non-contiguous covering the 5'-UTR to exon 1 and exons 3-7. All were traced to unaffected males in the family pedigrees. A new genome-wide approach of optical genome mapping was performed in families 1, 2, and 3 to delineate the breakpoints and orientation of the duplicated fragments. The extra copies were tandemly inserted into the upstream of DMD, preserving the integrity of ORF from the second copy. The pathogenicities were thus reclassified as likely benign. Our data highlight the importance of structural delineation by optical genome mapping in prenatal risk assessment of incidentally identified SVs involving DMD and other similar large dose-sensitive genes.

Assessing the necessity of screening ≤5 Mb segmental aneuploidy in routine PGT for aneuploidies

RESEARCH QUESTION

Does routine clinical practice require an increase in the resolution of preimplantation genetic testing for aneuploidies (PGT-A) to detect segmental aneuploidies ≤5 Mb?

DESIGN

This retrospective study analysed 963 trophectoderm biopsies from 346 couples undergoing PGT between 2019 and 2023. Segmental aneuploidies ≥1 Mb were reported. The characteristics, clinical interpretation and concordance of segmental aneuploidies ≤5 Mb were analysed.

RESULTS

The incidence of segmental aneuploidies was 15.1% (145/963) in blastocysts, with segmental aneuploidies of ≤5 Mb accounting for 2.3% (22/963). The size of the segmental aneuploidies showed a skewed distribution. Segmental aneuploidies ≤5 Mb were found to occur more frequently on the q arm of the chromosome, compared with the p arm. Losses of ≤5 Mb segmental aneuploidies were more prevalent than gains, with 17 deletions compared with 5 duplications. Of the segmental aneuploidies, 63.6% (14/22) ≤5 Mb were de novo, and 50.0% (7/14) of de-novo segmental aneuploidies were pathogenic/likely pathogenic (P/LP) copy number variations, accounting for 0.7% of 963 blastocysts. For blastocysts carrying ≤5 Mb segmental aneuploidies, a re-analysis of back-up biopsy samples showed that 35.7% of de-novo segmental aneuploidies (5/14) were not detected in the back-up samples. Cases were reported in which prenatal diagnosis (amniocentesis) revealed the absence of embryonic ≤5 Mb segmental aneuploidies detected at the blastocyst stage.

CONCLUSIONS

The incidence of P/LP de-novo ≤5 Mb segmental aneuploidies in human blastocysts is extremely low. There is no compelling need to increase the resolution of PGT-A to 5 Mb in routine clinical practice.

Clinical, pathological and genetic characteristics of 17 unrelated children with Alagille Syndrome

BACKGROUND

Alagille syndrome (ALGS) is a multisystem genetic disorder frequently characterized by hepatic manifestations. This study analyzed the clinical, pathological, and molecular genetic features of ALGS to improve the efficiency of clinical diagnosis.

METHODS

We retrospectively analyzed the clinical manifestations, pathological examination findings, and genetic testing results of 17 children diagnosed with ALGS based on the revised criteria and hospitalized at our center from January 2012 to January 2022.

RESULTS

The clinical manifestations are as follows: Cholestasis (16/17, 94%), characteristic facies (15/17, 88%), heart disease (12/16, 75%), butterfly vertebrae (12/17, 71%) and posterior embryotoxon (7/12, 58%). Among the 15 patients who underwent liver pathology examination, 13 (87%) were found to have varying degrees of bile duct paucity. Genetic testing was performed on 15 children, and pathogenic variants of the jagged canonical Notch ligand 1 (JAG1) gene were identified in 13 individuals, including 4 novel variants. No pathogenic variant in the notch homolog 2 (NOTCH2) gene were identified, and 2 children exhibited none of the aforementioned gene pathogenic variants. The median follow-up duration was 7 years. Of the remaining 15 patients (excluding 2 lost to follow-up), 11 remained stable, 4 deteriorated, and no patient died during the follow-up period.

CONCLUSIONS

Among children diagnosed with ALGS, cholestasis stands as the most common feature. To minimize the risk of misdiagnosis, genetic testing should be performed on children exhibiting cholestasis, followed by the application of the revised diagnostic criteria for ALGS. While pharmacological therapy has shown effectiveness for ALGS patients, liver transplantation may be considered in instances of severe pruritus.

Chromosomal Microarray Analysis in Fetuses with Ultrasound Abnormalities

Objective

To explore and evaluate the value of chromosomal microarray analysis (CMA) in prenatal diagnosis of fetuses with ultrasound abnormalities.

Methods

A retrospective analysis was performed on 370 fetuses with ultrasound abnormalities received invasive prenatal diagnosis at Meizhou People's Hospital from October 2022 to December 2023. Fetal specimens were analyzed by CMA, and the detection rates of aneuploidy and pathogenic (P)/likely pathogenic (LP) copy number variations (CNVs) in ultrasound structural abnormalities (malformations of fetal anatomy) and non-structural abnormalities (abnormalities of fetal nonanatomical structure) were analyzed.

Results

There were 114 (30.8%) cases with isolated ultrasound structural abnormalities, 226 (61.1%) cases with isolated non-structural abnormalities (182 isolated ultrasound soft markers abnormalities, 30 isolated fetal growth restriction (FGR), and 8 isolated abnormalities of amniotic fluid volume), and 30 (8.1%) cases with both structural and non-structural abnormalities. The overall detection rate of aneuploidy and P/LP CNVs in isolated ultrasonic structural abnormalities was 5.3%, among which cardiovascular system abnormalities were the highest. In addition, the largest number of fetuses with non-structural abnormalities was nuchal translucency (NT) thickening (n = 81), followed by ventriculomegaly (n = 29), and nasal bone dysplasia (n = 24). The detection rate of chromosomal abnormalities of fetuses with abnormal ultrasound soft markers was 9.9%, and the detection rate in single abnormal ultrasound soft marker, and multiple ultrasound soft markers abnormalities was 9.7% (16/165) and 11.8% (2/17), respectively. Moreover, the detection rate of chromosomal abnormalities of fetuses with FGR and structural abnormalities combined with non-structural abnormalities was 6.7% (2/30), and 13.3% (4/30), respectively.

Conclusion

The incidence of chromosomal abnormalities (aneuploidy and P/LP CNVs) varies among different fetal ultrasound abnormalities.

[Clinical and genetic features of children with 3-methylcrotonyl-coenzyme A carboxylase deficiency: an analysis of six cases]

OBJECTIVES

To investigate the clinical and genetic features of children with 3-methylcrotonyl-coenzyme A carboxylase deficiency (MCCD).

METHODS

A retrospective analysis was conducted on the clinical manifestations and genetic testing results of six children with MCCD who attended Children's Hospital Affiliated to Zhengzhou University from January 2018 to October 2023.

RESULTS

Among the six children with MCCD, there were 4 boys and 2 girls, with a mean age of 7 days at the time of attending the hospital and 45 days at the time of confirmed diagnosis. Of all children, one had abnormal urine odor and five had no clinical symptoms. All six children had increases in blood 3-hydroxyisovaleryl carnitine and urinary 3-hydroxyisovaleric acid and 3-methylcrotonoylglycine, and five of them had a reduction in free carnitine. A total of six mutations were identified in the MCCC1 gene, i.e., c.1630del(p.R544Dfs*2), c.269A>G(p.D90G), c.1609T>A(p.F537I), c.639+2T>A, c.761+1G>T, and c.1331G>A(p.R444H), and three mutations were identified in the MCCC2 gene, i.e., c.838G>T(p.D280Y), c.592C>T(p.Q198*,366), and c.1342G>A(p.G448A). Among these mutations, c.269A>G(p.D90G) and c.1609T>A(p.F537I) had not been previously reported in the literature. There was one case of maternal MCCD, and the child carried a heterozygous mutation from her mother. Five children with a reduction in free carnitine were given supplementation of L-carnitine, and free carnitine was restored to the normal level at the last follow-up visit.

CONCLUSIONS

This study identifies two new mutations, c.269A>G(p.D90G) and c.1609T>A(p.F537I), thereby expanding the mutation spectrum of the MCCC1 gene. A combination of blood amino acid and acylcarnitine profiles, urine organic acid analysis, and genetic testing can facilitate early diagnosis and treatment of MCCD, and provide essential data for genetic counseling.

The yield of genetic workup for middle-aged and elderly patients with neurological disorders in a real-world setting

Genetic workup is becoming increasingly common in the clinical assessment of neurological disorders. We evaluated its yield among middle-aged and elderly neurological patients, in a real-world context. This retrospective study included 368 consecutive Israeli patients aged 50 years and older (202 [54.9%] males), who were referred to a single neurogenetics clinic between 2017 and mid-2023. All had neurological disorders, without a previous molecular diagnosis. Demographic, clinical and genetic data were collected from medical records. The mean age at first genetic counseling at the clinic was 62.3 ± 7.8 years (range 50-85 years), and the main indications for referral were neuromuscular, movement and cerebrovascular disorders, as well as cognitive impairment and dementia. Out of the 368 patients, 245 (66.6%) underwent genetic testing that included exome sequencing (ES), analysis of nucleotide repeat expansions, detection of specific mutations, targeted gene panel sequencing or chromosomal microarray analysis. Overall, 80 patients (21.7%) received a molecular diagnosis due to 36 conditions, accounting for 32.7% of the patients who performed genetic testing. The diagnostic rates were highest for neuromuscular (58/186 patients [31.2%] in this group, 39.2% of 148 tested individuals) and movement disorders (14/79 [17.7%] patients, 29.2% of 48 tested), but lower for other disorders. Testing of nucleotide repeat expansions and ES provided a diagnosis to 28/73 (38.4%) and 19/132 (14.4%) individuals, respectively. Based on our findings, genetic workup and testing are useful in the diagnostic process of neurological patients aged ≥50 years, in particular for those with neuromuscular and movement disorders.

Genome sequencing reveals novel causative structural and single nucleotide variants in Pakistani families with congenital hypogonadotropic hypogonadism

BACKGROUND/OBJECTIVES

This study aims to elucidate the genetic causes of congenital hypogonadotropic hypogonadism (CHH), a rare genetic disorder resulting in GnRH deficiency, in six families from Pakistan.

METHODS

Eighteen DNA samples from six families underwent genome sequencing followed by standard evaluation for pathogenic single nucleotide variants (SNVs) and small indels. All families were subsequently analyzed for pathogenic copy number variants (CNVs) using CoverageMaster.

RESULTS

Novel pathogenic homozygous SNVs in known CHH genes were identified in four families: two families with variants in GNRHR, and two others harboring KISS1R variants. Subsequent investigation of CNVs in the remaining two families identified novel unique large deletions in ANOS1.

CONCLUSION

A combined, systematic analysis of single nucleotide and CNVs helps to improve the diagnostic yield for variants in patients with CHH.

Utility of Genome Sequencing After Nondiagnostic Exome Sequencing in Unexplained Pediatric Epilepsy

Importance

Epilepsy is the most common neurological disorder of childhood. Identifying genetic diagnoses underlying epilepsy is critical to developing effective therapies and improving outcomes. Most children with non-acquired (unexplained) epilepsy remain genetically unsolved, and the utility of genome sequencing after nondiagnostic exome sequencing is unknown.

Objective

To determine the diagnostic (primary) and clinical (secondary) utility of genome sequencing after nondiagnostic exome sequencing in individuals with unexplained pediatric epilepsy.

Design

This cohort study performed genome sequencing and comprehensive analyses for 125 participants and available biological parents enrolled from August 2018 to May 2023, with data analysis through April 2024 and clinical return of diagnostic and likely diagnostic genetic findings. Clinical utility was evaluated.

Setting

Pediatric referral center.

Participants

Participants with unexplained pediatric epilepsy and previous nondiagnostic exome sequencing; biological parents when available.

Exposures

Short-read genome sequencing and analysis.

Main Outcomes and Measures

Primary outcome measures were the diagnostic yield of genome sequencing, defined as the percentage of participants receiving a diagnostic or likely diagnostic genetic finding, and the unique diagnostic yield of genome sequencing, defined as the percentage of participants receiving a diagnostic or likely diagnostic genetic finding that required genome sequencing. The secondary outcome measure was clinical utility of genome sequencing, defined as impact on evaluation, treatment, or prognosis for the participant or their family.

Results

125 participants (58 [46%] female) were enrolled with median age at seizure onset 3 [IQR 1.25, 8] years, including 44 (35%) with developmental and epileptic encephalopathies. The diagnostic yield of genome sequencing was 7.2% (9/125), with diagnostic genetic findings in five cases and likely diagnostic genetic findings in four cases. Among the solved cases, 7/9 (78%) required genome sequencing for variant detection (small copy number variant, three noncoding variants, and three difficult to sequence small coding variants), for a unique diagnostic yield of genome sequencing of 5.6% (7/125). Clinical utility was documented for 4/9 solved cases (44%).

Conclusions and Relevance

These findings suggest that genome sequencing can have diagnostic and clinical utility after nondiagnostic exome sequencing and should be considered for patients with unexplained pediatric epilepsy.

Analysis of parental origin of de novo pathogenic CNVs in patients with intellectual disability

Chromosomal Microarray Analysis (CMA) has increased the comprehension of the mechanisms of copy number variation (CNV) formation, classification of these rearrangements, type of recurrence, and its origin, and has also been a powerful approach to identifying CNVs in individuals with intellectual disability. The aim of this study was to establish the parental origin of de novo pathogenic CNV in a cohort of patients with intellectual disability from the public health system of Goiás-Brazil. CMA was done in 76 trios and we identified 15 de novo pathogenic CNVs in 12 patients with intellectual disability. In a total of 15 de novo pathogenic CNV, 60% were derived from the maternal germline and 40% from the paternal germline. CNV flanked by low copy repeats (LCR) were identified in 46.7% and most of them were of maternal origin. No significant association was observed between paternal age and the mutation rate of de novo CNVs. The presence of high-identity LCRs increases the occurrence of CNV formation mediated by non-allelic homologous recombination and the majority of paternal CNVs are non-recurrent. The mechanism of formation of these CNV may have been by microhomology-mediated break-induced replication or non-homologous end joining.

Genotype-phenotype spectrum and correlation of PHARC Syndrome due to pathogenic ABHD12 variants

BACKGROUND

A comprehensive understanding of the genetic basis of rare diseases and their regulatory mechanisms is essential for human molecular genetics. However, the genetic mutant spectrum of pathogenic genes within the Chinese population remains underrepresented. Here, we reported previously unreported functional ABHD12 variants in two Chinese families and explored the correlation between genetic polymorphisms and phenotypes linked to PHARC syndrome.

METHODS

Participants with biallelic pathogenic ABHD12 variants were recruited from the Chinese Deafness Genetics Cohort. These participants underwent whole-genome sequencing. Subsequently, a comprehensive literature review was conducted.

RESULTS

Two Han Chinese families were identified, one with a compound heterozygous variant and the other with a novel homozygous variant in ABHD12. Among 65 PHARC patients, including 62 from the literature and 3 from this study, approximately 90% (57 out of 63) exhibited hearing loss, 82% (50 out of 61) had cataracts, 82% (46 out of 56) presented with retinitis pigmentosa, 79% (42 out of 53) experienced polyneuropathy, and 63% (36 out of 57) displayed ataxia. Seventeen different patterns were observed in the five main phenotypes of PHARC syndrome. A total of 33 pathogenic variants were identified in the ABHD12. Compared with other genotypes, individuals with biallelic truncating variants showed a higher incidence of polyneuropathy (p = 0.006), but no statistically significant differences were observed in the incidence of hearing loss, ataxia, retinitis pigmentosa and cataracts.

CONCLUSIONS

The diagnosis of PHARC syndrome is challenging because of its genetic heterogeneity. Therefore, exploring novel variants and establishing genotype-phenotype correlations can significantly enhance gene diagnosis and genetic counseling for this complex disease.

X-linked severe combined immunodeficiency complicated by disseminated bacillus Calmette-Guérin disease caused by a novel pathogenic mutation in exon 3 of the IL2RG gene: a case report and literature review

X-linked severe combined immunodeficiency (X-SCID), caused by mutations in the gamma-chain gene of the interleukin-2 receptor (IL2RG), is a prevalent form of SCID characterized by recurrent and fatal opportunistic infections that occur early in life. The incidence of disseminated bacillus Calmette-Guérin (BCG) disease among children with SCID is much higher than in the general population. Here, we report the case of a 4-month-old male infant who presented with subcutaneous induration, fever, an unhealed BCG vaccination site, and hepatosplenomegaly. Metagenomic next-generation sequencing in blood, and the detection of gastric juice and skin nodule pus all confirmed the infection of Mycobacterium tuberculosis. Lymphocyte subset analysis confirmed the presence of T-B+NK immunodeficiency. Whole-exome and Sanger sequencing revealed a novel microdeletion insertion mutation (c.316_318delinsGTGAT p.Leu106ValfsTer42) in the IL2RG gene, resulting in a rare shift in the amino acid sequence of the coding protein. Consequently, the child was diagnosed with X-SCID caused by a novel mutation in IL2RG, complicated by systemic disseminated BCG disease. Despite receiving systemic anti-infection treatment and four days of hospitalization, the patient died three days after discharge. To the best of our knowledge, this specific IL2RG mutation has not been previously reported. In our systemic review, we outline the efficacy of systemic anti-tuberculosis therapy, hematopoietic stem cell transplantation, and gene therapy in children with SCID and BCG diseases caused by IL2RG gene mutation.

From Nonfunctioning Adrenocortical Cancer to Biochemically Silent Paraganglioma Associated with SDHB Mutation: An Uncommon Presentation of a Patient with a Retroperitoneal Mass

The combination of clinical characteristics and diagnostic exams including imaging, laboratory, and molecular tests help in the differential diagnosis of retroperitoneal lesions. We report a 41-year-old male with a metastatic retroperitoneal lesion with atypical characteristics, displaying pathological findings consistent with both nonsecretory pheochromocytomas/paragangliomas and adrenal cortex carcinoma. The patient was examined for abdominal pain, weight loss, and hypertension. Abdominal computed tomography showed a 21 × 8 × 10-cm right retroperitoneal mass. He was initially diagnosed as pheochromocytoma/paraganglioma (PHEO/PGL). However, the diagnosis was later changed to adrenocortical carcinoma based on histopathological features of the metastatic lesions and the findings of normal urinary levels of catecholamines/metanephrines. Systemic chemotherapy and abdominal radiotherapy were performed, in addition to multiple surgical resections, with no satisfactory response. The indolent course of the disease and minimal impact on the patient's performance status led to a genetic evaluation which resulted in the identification of a germline mutation in the succinate dehydrogenase complex subunit B (SDHB). An immunohistology review of previous slides was consistent with the hypothesis of a neuroendocrine tumor. Forty percent of the patients with PHEO/PGL have an underlying germline mutation. SDHB mutation is frequently associated with metastatic disease and dominant secretion of noradrenaline and/or dopamine. In addition to the metastatic disease, few cases with the mutations can be a biochemically silent PHEO/PGL. We concluded that the patient presented a metastatic abdominal paraganglioma associated with an SDHB mutation and we reinforced the need to perform genetic screening for all adrenal/extra-adrenal lesions characteristic of PHEO/PGL.

Optical genome mapping identifies a homozygous deletion in the non-coding region of the SCN9A gene in individuals from the same family with congenital insensitivity to pain

We report an index patient with complete insensitivity to pain and a history of painless fractures, joint hypermobility, and behavioral problems. The index patient descends from a family with notable cases among his maternal relatives, including his aunt and his mother's first cousin, both of whom suffer from congenital insensitivity to pain. The patient had normal results for prior genetic testing: fragile-X syndrome testing, chromosomal microarray analysis, and exome sequencing. Optical genome mapping detected a homozygous deletion affecting the noncoding 5' untranslated region (UTR) and the first non-coding exon of the SCN9A gene in all affected family members, compatible with recessive disease transmission. Pathogenic homozygous loss-of-function variants in the SCN9A gene are associated with impaired pain sensation in humans. Optical genome mapping can thus detect pathogenic structural variants in patients without molecular etiology by standard diagnostic procedures and is a more accessible diagnostic tool than short-read or long-read whole-genome sequencing.

A novel de novo synonymous variant in GREB1L impacts the mRNA splicing associated with aplasia of the urogenital system

GREB1-like retinoic acid receptor coactivator (GREB1L) gene is associated with autosomal dominant renal hypodysplasia/aplasia 3 (RHDA3) and deafness, autosomal dominant 80 (DFNA80). Among the GREB1L variants reported, most of them are missense or frameshift, while no pathogenic synonymous variants have been recorded. Classical theory paid little attention to synonymous variants and classified it as nonpathogenic; however, recent studies suggest that the variants might be equally important. Here, we report a 7-year-old girl with new symptoms of clitoromegaly, uterovaginal, and ovarian agenesis as well as right kidney missing. A novel de novo GREB1L synonymous variant (NM_001142966: c.4731C>T, p.G1577=) was identified via whole exome sequencing. The variant was predicted to be disease-causing through in silico analysis and was classified as likely pathogenic. Minigene splicing assays confirmed a 6 bp deletion in mutant cDNA comparing with the wild type, leading to two amino acids lost in GREB1L protein. Secondary and tertiary structure modeling showed alterations in protein structure. Our finding reveals a novel GREB1L variant with a new phenotype of urogenital system and is the first to report a pathogenic synonymous variant in GREB1L which affects mRNA splicing, suggesting synonymous variants cannot be ignored in prenatal diagnosis and genetic counseling.

Congenital anterior segment ocular disorders: Genotype-phenotype correlations and emerging novel mechanisms

Development of the anterior segment of the eye requires reciprocal sequential interactions between the arising tissues, facilitated by numerous genetic factors. Disruption of any of these processes results in congenital anomalies in the affected tissue(s) leading to anterior segment disorders (ASD) including aniridia, Axenfeld-Rieger anomaly, congenital corneal opacities (Peters anomaly, cornea plana, congenital primary aphakia), and primary congenital glaucoma. Current understanding of the genetic factors involved in ASD remains incomplete, with approximately 50% overall receiving a genetic diagnosis. While some genes are strongly associated with a specific clinical diagnosis, the majority of known factors are linked with highly variable phenotypic presentations, with pathogenic variants in FOXC1, CYP1B1, and PITX2 associated with the broadest spectrum of ASD conditions. This review discusses typical clinical presentations including associated systemic features of various forms of ASD; the latest functional data and genotype-phenotype correlations related to 25 ASD factors including newly identified genes; promising novel candidates; and current and emerging treatments for these complex conditions. Recent developments of interest in the genetics of ASD include identification of phenotypic expansions for several factors, discovery of multiple modes of inheritance for some genes, and novel mechanisms including a growing number of non-coding variants and alleles affecting specific domains/residues and requiring further studies.

Cardiac conduction disorders in young adults: Clinical characteristics and genetic background of an underestimated population

BACKGROUND

Cardiac conduction disorder (CCD) in patients <50 years old is a rare and mostly unknown condition.

OBJECTIVE

We aimed to assess clinical characteristics and genetic background of patients <50 years old with CCD of unknown origin.

METHODS

We retrospectively reviewed a consecutive series of patients with a diagnosis of CCD before the age of 50 years referred to our center between January 2019 and December 2021. Patients underwent complete clinical examination and genetic evaluation.

RESULTS

We enrolled 39 patients with a median age of 40 years (28-47 years) at the onset of symptoms. A cardiac implantable electronic device was implanted in 69% of the patients. In 15 of 39 CCD index patients (38%), we found a total of 13 different gene variations (3 pathogenic, 6 likely pathogenic, and 4 variants of uncertain significance), mostly in 3 genes (SCN5A, TRPM4, and LMNA). In our cohort, genetic testing led to the decision to implant an implantable cardioverter-defibrillator in 2 patients for the increased risk of sudden cardiac death.

CONCLUSION

Patients with the occurrence of CCD before the age of 50 years present with a high rate of pathologic gene variations, mostly in 3 genes (SCN5A, TRPM4, and LMNA). The presence of pathogenic variations may add information about the prognosis and lead to an individualized therapeutic approach.

Natural history of adults with KBG syndrome: A physician-reported experience

PURPOSE

KBG syndrome (KBGS) is a rare neurodevelopmental syndrome caused by haploinsufficiency of ANKRD11. The childhood phenotype is extensively reported but limited for adults. Thus, we aimed to delineate the clinical features of KBGS.

METHODS

We collected physician-reported data of adults with molecularly confirmed KBGS through an international collaboration. Moreover, we undertook a systematic literature review to determine the scope of previously reported data.

RESULTS

The international collaboration identified 36 adults from 31 unrelated families with KBGS. Symptoms included mild/borderline intellectual disability (n = 22); gross and/or fine motor difficulties (n = 15); psychiatric and behavioral comorbidities including aggression, anxiety, reduced attention span, and autistic features (n = 26); nonverbal (n = 3), seizures with various seizure types and treatment responses (n = 10); ophthalmological comorbidities (n = 20). Cognitive regression during adulthood was reported once. Infrequent features included dilatation of the ascending aorta (n = 2) and autoimmune conditions (n = 4). Education, work, and residence varied, and the diversity of professional and personal roles highlighted the range of abilities seen. The literature review identified 154 adults reported across the literature, and we have summarized the features across both data sets.

CONCLUSION

Our study sheds light on the long-term neurodevelopmental outcomes, seizures, behavioral and psychiatric features, and education, work, and living arrangements for adults with KBGS.

Ocular manifestations of CHARGE syndrome in a pediatric cohort with genotype/phenotype analysis

CHARGE syndrome is a rare multi-system condition associated with CHD7 variants. However, ocular manifestations and particularly ophthalmic genotype-phenotype associations, are not well-studied. This study evaluated ocular manifestations and genotype-phenotype associations in pediatric patients with CHARGE syndrome. A retrospective chart review included pediatric patients under 20 years-old with clinical diagnosis of CHARGE syndrome and documented ophthalmic examination. Demographics, genetic testing, and ocular findings were collected. Comprehensive literature review enhanced the genotype-phenotype analysis. Forty-two patients (20 male) underwent eye examination at an average age of 9.45 ± 6.52 years-old. Thirty-nine (93%) had ophthalmic manifestations in at least one eye. Optic nerve/chorioretinal colobomas were most common (38 patients), followed by microphthalmia (13), cataract (6), and iris colobomas (4). Extraocular findings included strabismus (32 patients), nasolacrimal duct obstructions (11, 5 with punctal agenesis), and cranial nerve VII palsy (10). Genotype-phenotype analyses (27 patients) showed variability in ocular phenotypes without association to location or variant types. Splicing (10 patients) and frameshift (10) variants were most prevalent. Patients with CHARGE syndrome may present with a myriad of ophthalmic manifestations. There is limited data regarding genotype-phenotype correlations and additional studies are needed.

Rapid Whole-Genome Sequencing and Clinical Management in the PICU: A Multicenter Cohort, 2016-2023

OBJECTIVES

Analysis of the clinical utility of rapid whole-genome sequencing (rWGS) outside of the neonatal period is lacking. We describe the use of rWGS in PICU and cardiovascular ICU (CICU) patients across four institutions.

DESIGN

Ambidirectional multisite cohort study.

SETTING

Four tertiary children's hospitals.

PATIENTS

Children 0-18 years old in the PICU or CICU who underwent rWGS analysis, from May 2016 to June 2023.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 133 patients underwent clinical, phenotype-driven rWGS analysis, 36 prospectively. A molecular diagnosis was identified in 79 patients (59%). Median (interquartile range [IQR]) age was 6 months (IQR 1.2 mo-4.6 yr). Median time for return of preliminary results was 3 days (IQR 2-4). In 79 patients with a molecular diagnosis, there was a change in ICU management in 19 patients (24%); and some change in clinical management in 63 patients (80%). Nondiagnosis changed management in 5 of 54 patients (9%). The clinical specialty ordering rWGS did not affect diagnostic rate. Factors associated with greater odds ratio (OR [95% CI]; OR [95% CI]) of diagnosis included dysmorphic features (OR 10.9 [95% CI, 1.8-105]) and congenital heart disease (OR 4.2 [95% CI, 1.3-16.8]). Variables associated with greater odds of changes in management included obtaining a genetic diagnosis (OR 16.6 [95% CI, 5.5-62]) and a shorter time to genetic result (OR 0.8 [95% CI, 0.76-0.9]). Surveys of pediatric intensivists indicated that rWGS-enhanced clinical prognostication ( p < 0.0001) and contributed to a decision to consult palliative care ( p < 0.02).

CONCLUSIONS

In this 2016-2023 multiple-PICU/CICU cohort, we have shown that timely genetic diagnosis is feasible across institutions. Application of rWGS had a 59% (95% CI, 51-67%) rate of diagnostic yield and was associated with changes in critical care management and long-term patient management.

Genetic Testing in Pediatric Epilepsy: Tools, Tips, and Navigating the Traps

With the advent of high-throughput sequencing and computational methods, genetic testing has become an integral part of contemporary clinical practice, particularly in epilepsy. The toolbox for genetic testing has evolved from conventional chromosomal microarray and epilepsy gene panels to state-of-the-art sequencing techniques in the modern genomic era. Beyond its potential for therapeutic benefits through precision medicine, optimizing the choice of antiseizure medications, or exploring nonpharmacological therapeutic modalities, genetic testing carries substantial diagnostic, prognostic, and personal implications. Developmental and epileptic encephalopathies, the coexistence of neurodevelopmental comorbidities, early age of epilepsy onset, unexplained drug-refractory epilepsy, and positive family history have demonstrated the highest likelihood of yielding positive genetic test results. Given the diagnostic efficacy across different testing modalities, reducing costs of next-generation sequencing tests, and genetic diversity of epilepsies, exome sequencing or genome sequencing, where feasible and available, have been recommended as the first-tier test. Comprehensive clinical phenotyping at the outset, corroborative evidence from radiology and electrophysiology-based investigations, reverse phenotyping, and periodic reanalysis are some of the valuable strategies when faced with inconclusive test results. In this narrative review, the authors aim to simplify the approach to genetic testing in epilepsy by guiding on the selection of appropriate testing tools in the indicated clinical scenarios, addressing crucial aspects during pre- and post-test counseling sessions, adeptly navigating the traps posed by uncertain or negative genetic variants, and paving the way forward to the emerging testing modalities beyond DNA sequencing.

Correlation between maternal serum biomarkers and the risk of fetal chromosome copy number variants: a single-center retrospective study

OBJECTIVE

To explore the association between the concentration of maternal serum biomarkers and the risk of fetal carrying chromosome copy number variants (CNVs).

METHODS

Pregnant women identified as high risk in the second-trimester serological triple screening and underwent traditional amniotic fluid karyotype analysis, along with comparative genomic hybridization array (aCGH)/copy number variation sequencing (CNV-seq), were included in the study. We divided the concentration of serum biomarkers, free beta-human chorionic gonadotropin (fβ-hCG), alpha fetoprotein (AFP) and unconjugated estriol (uE3), into three levels: abnormally low, normal and abnormally high. The prevalence of abnormally low, normal and abnormally high serum fβ-hCG, AFP and uE3 levels in pregnant women with aberrant aCGH/CNV-seq results and normal controls was calculated.

RESULTS

Among the 2877 cases with high risk in the second-trimester serological triple screening, there were 98 chromosome abnormalities revealed by karyotype analysis, while 209 abnormalities were detected by aCGH/CNVseq (P＜0.001) . The carrying rate of aberrant CNVs increased significantly when the maternal serum uE3 level was less than 0.4 multiple of median (MoM) of corresponding gestational weeks compared to normal controls, while the carrying rate of aberrant CNVs decreased significantly when the maternal serum fβ-hCG level was greater than 2.5 MoM compared to normal controls. No significant difference was found in the AFP group.

CONCLUSION

Low serum uE3 level (<0.4 MoM) was associated with an increased risk of aberrant CNVs.

Investigating copy number variants in schizophrenia pedigrees using a new consensus pipeline called PECAN

Copy number variants (CNVs) have been implicated in many human diseases, including psychiatric disorders. Whole genome sequencing offers advantages in CNV calling compared to previous array-based methods. Here we present a robust and transparent CNV calling pipeline, PECAN (PEdigree Copy number vAriaNt calling), for short-read, whole genome sequencing data, comprised of a novel combination of four calling methods and structural variant genotyping. This method is scalable and can incorporate pedigree information to retain lower-confidence CNVs that would otherwise be discarded. We have robustly benchmarked PECAN using gold-standard CNV calls for two well-established evaluation samples, NA12878 and HG002, showing that PECAN performs with high precision and recall on both datasets, outperforming another pedigree-based CNV calling pipeline. As part of this work, we provide a list of high-confidence gold standard CNVs for the NA12878 reference sample, curated from multiple studies. We applied PECAN to a collection of pedigrees multiply affected with schizophrenia and identified a rare deletion that perfectly co-segregates with schizophrenia in one of the pedigrees. The CNV overlaps the gene PITRM1, which has been implicated in a complex phenotype including ataxia, developmental delay, and schizophrenia-like episodes in affected adults.

Fetal agenesis of corpus callosum: chromosomal copy number abnormalities and postnatal follow-up

OBJECTIVE

Agenesis of the corpus callosum (ACC) is an anomaly that can occur in fetuses during pregnancy. However, there is currently no treatment for fetal ACC. Therefore, we conducted a retrospective analysis of obstetric outcomes of fetal ACC to explore the relationship between fetal ACC phenotypes and chromosomal copy number abnormalities.

METHODS AND RESULTS

Amniotic fluid or umbilical cord blood were extracted from pregnant women with fetal ACC for karyotype analysis and chromosomal microarray analysis (CMA). Among the 48 fetuses with ACC, 22 (45.8%, 22/48) had isolated ACC, and 26 (54.2%, 26/48) had non-isolated ACC. Chromosomal abnormalities were detected via karyotype analysis in four cases. In addition to the four cases of pathogenic copy number variations (CNVs) detected using karyotype analysis, CMA revealed two cases of pathogenic CNVs with 17q12 microduplication and 16p12.2 microdeletion. The obstetric outcomes of 26 patients with non-isolated ACC were followed up, and 17 chose to terminate the pregnancy. In addition, seven of the nine cases with non-isolated ACC showed no obvious abnormality during postnatal follow-up, whereas only one case with normal CMA showed an abnormal phenotype at six months. Of the 22 patients with isolated ACC, six chose to terminate the pregnancy. Postnatal follow-up of 16 isolated ACC cases revealed only one with benign CNV, presenting with intellectual disability.

CONCLUSION

Pregnant women with fetal ACC should be offered prenatal CMA, particularly non-isolated ACC. Patients with ACC should undergo prolonged postnatal follow-up, and appropriate intervention should be provided if necessary.

Clinical cases series and pathogenesis of Lamb-Shaffer syndrome in China

BACKGROUND

Lamb-Shaffer syndrome (LAMSHF, OMIM: 616803) is a rare neurodevelopmental disorder characterized by global developmental delay, intellectual disability, poor expressive speech, which is attributed to haploinsufficiency by heterozygous variants of SOX5 gene (SRY-Box Transcription Factor 5, HGNC: 11201) on chromosome 12p12. A total of 113 cases have been reported in the world, however, only 3 cases have been reported.in China. Here, we aimed to report novel variants of SOX5 gene and provide examples for clinical diagnosis by reporting the clinical phenotype of a series of Chinese patients with LAMSHF.

METHODS

This study retrospectively collected the information of families of LAMSHF patients in China. Whole Exome Sequencing (WES) were performed to confirm the diagnosis of 4 children with unexplained developmental delay or epilepsy. A minigene splicing assay was used to verify whether the splice variant affected splicing. Meanwhile, a literature review was conducted to analyze the clinical and genetic characteristics of patients with LAMSHF.

RESULTS

Three of the LAMSHF patients had a de novo heterozygous mutation in the SOX5 gene respectively, c.290delC (p.Pro97fs*30), chr12:23686019_24048958del, c.1772-1C > A, and the remaining one had a mutation inherited from his father, c.1411C > T (p.Arg471*). The main clinical manifestations of these children were presented with global developmental delays, and one of them also had seizures. And the results of the minigene experiment indicated that the splice variant, c.1772-1C > A, transcribed a novel mRNA product which leaded to the formation of a truncated protein.

CONCLUSIONS

Through a comprehensive review and analysis of existing literature and this study showed intellectual disability, speech delay and facial dysmorphisms were common clinical manifestation, while the seizures and EEG abnormalities were rare (21/95, 22.16%). Notably, we represent the largest sample size of LAMSHF in Asia that encompasses previously unreported SOX5 gene mutation, and a minigene testing have been conducted to validate the pathogenicity of the c.1772-1C > A splice variant. The research further expands the phenotype and genotype of LAMSHF while offers novel insights for potential pathogenicity of genes locus.

Nablus mask-like facial syndrome: Report of an atypical case with 8q21.3-q22.1 deletion

Nablus mask-like facial syndrome (NMLFS) is a rare condition characterized by unique facial features, initially described in a 4-year-old boy from Nablus, Palestine. These features include expressionless facial appearance, tight facial skin, blepharophimosis, sparse eyebrows, and a flat nose. Genetic studies have identified a deletion of 8q22.1 as the cause of the syndrome, however while 26 patients have been reported with the deletion, only 13 displayed the characteristic facial features. Here we report on a 35-year-old male with 8q21.3-q22.1 deletion identified by whole exome sequencing and Chromosomal microarray analysis (CMA) that presents with typical and atypical features, including neurodevelopmental disorder, mild facial features, and myopathy, which has not been described in a patient with NMLFS to date. Further research will be required to understand the underlying pathogenetic mechanism of this rare genetic disorder.

Multisite Evaluation and Validation of Optical Genome Mapping for Prenatal Genetic Testing

Prenatal diagnostic testing of amniotic fluid, chorionic villi, or more rarely, fetal cord blood is recommended following a positive or unreportable noninvasive cell-free fetal DNA test, abnormal maternal biochemical serum screen, abnormal ultrasound, or increased genetic risk for a cytogenomic abnormality based on family history. Although chromosomal microarray is recommended as the first-tier prenatal diagnostic test, in practice, multiple assays are often assessed in concert to achieve a final diagnostic result. The use of multiple methodologies is costly, time consuming, and labor intensive. Optical genome mapping (OGM) is an emerging technique with application for prenatal diagnosis because of its ability to detect and resolve, in a single assay, all classes of pathogenic cytogenomic aberrations. In an effort to characterize the potential of OGM as a novel alternative to traditional standard of care (SOC) testing of prenatal samples, OGM was performed on a total of 200 samples representing 123 unique cases, which were previously tested with SOC methods (92/123 = 74.7% cases tested with at least two SOCs). OGM demonstrated an overall accuracy of 99.6% when compared with SOC methods, a positive predictive value of 100%, and 100% reproducibility between sites, operators, and instruments. The standardized workflow, cost-effectiveness, and high-resolution cytogenomic analysis demonstrate the potential of OGM to serve as a first-tier test for prenatal diagnosis.

DNA methylation episignature and comparative epigenomic profiling for Pitt-Hopkins syndrome caused by TCF4 variants

Pitt-Hopkins syndrome (PTHS) is a neurodevelopmental disorder caused by pathogenic variants in TCF4, leading to intellectual disability, specific morphological features, and autonomic nervous system dysfunction. Epigenetic dysregulation has been implicated in PTHS, prompting the investigation of a DNA methylation (DNAm) "episignature" specific to PTHS for diagnostic purposes and variant reclassification and functional insights into the molecular pathophysiology of this disorder. A cohort of 67 individuals with genetically confirmed PTHS and three individuals with intellectual disability and a variant of uncertain significance (VUS) in TCF4 were studied. The DNAm episignature was developed with an Infinium Methylation EPIC BeadChip array analysis using peripheral blood cells. Support vector machine (SVM) modeling and clustering methods were employed to generate a DNAm classifier for PTHS. Validation was extended to an additional cohort of 11 individuals with PTHS. The episignature was assessed in relation to other neurodevelopmental disorders and its specificity was examined. A specific DNAm episignature for PTHS was established. The classifier exhibited high sensitivity for TCF4 haploinsufficiency and missense variants in the basic-helix-loop-helix domain. Notably, seven individuals with TCF4 variants exhibited negative episignatures, suggesting complexities related to mosaicism, genetic factors, and environmental influences. The episignature displayed degrees of overlap with other related disorders and biological pathways. This study defines a DNAm episignature for TCF4-related PTHS, enabling improved diagnostic accuracy and VUS reclassification. The finding that some cases scored negatively underscores the potential for multiple or nested episignatures and emphasizes the need for continued investigation to enhance specificity and coverage across PTHS-related variants.

DNA methylation analysis in patients with neurodevelopmental disorders improves variant interpretation and reveals complexity

Analysis of genomic DNA methylation by generating epigenetic signature profiles (episignatures) is increasingly being implemented in genetic diagnosis. Here we report our experience using episignature analysis to resolve both uncomplicated and complex cases of neurodevelopmental disorders (NDDs). We analyzed 97 NDDs divided into (1) a validation cohort of 59 patients with likely pathogenic/pathogenic variants characterized by a known episignature and (2) a test cohort of 38 patients harboring variants of unknown significance or unidentified variants. The expected episignature was obtained in most cases with likely pathogenic/pathogenic variants (53/59 [90%]), a revealing exception being the overlapping profile of two SMARCB1 pathogenic variants with ARID1A/B:c.6200, confirmed by the overlapping clinical features. In the test cohort, five cases showed the expected episignature, including (1) novel pathogenic variants in ARID1B and BRWD3; (2) a deletion in ATRX causing MRXFH1 X-linked mental retardation; and (3) confirmed the clinical diagnosis of Cornelia de Lange (CdL) syndrome in mutation-negative CdL patients. Episignatures analysis of the in BAF complex components revealed novel functional protein interactions and common episignatures affecting homologous residues in highly conserved paralogous proteins (SMARCA2 M856V and SMARCA4 M866V). Finally, we also found sex-dependent episignatures in X-linked disorders. Implementation of episignature profiling is still in its early days, but with increasing utilization comes increasing awareness of the capacity of this methodology to help resolve the complex challenges of genetic diagnoses.

An Integrated Transcriptomics and Genomics Approach Detects an X/Autosome Translocation in a Female with Duchenne Muscular Dystrophy

Duchenne and Becker muscular dystrophies, caused by pathogenic variants in DMD, are the most common inherited neuromuscular conditions in childhood. These diseases follow an X-linked recessive inheritance pattern, and mainly males are affected. The most prevalent pathogenic variants in the DMD gene are copy number variants (CNVs), and most patients achieve their genetic diagnosis through Multiplex Ligation-dependent Probe Amplification (MLPA) or exome sequencing. Here, we investigated a female patient presenting with muscular dystrophy who remained genetically undiagnosed after MLPA and exome sequencing. RNA sequencing (RNAseq) from the patient's muscle biopsy identified an 85% reduction in DMD expression compared to 116 muscle samples included in the cohort. A de novo balanced translocation between chromosome 17 and the X chromosome (t(X;17)(p21.1;q23.2)) disrupting the DMD and BCAS3 genes was identified through trio whole genome sequencing (WGS). The combined analysis of RNAseq and WGS played a crucial role in the detection and characterisation of the disease-causing variant in this patient, who had been undiagnosed for over two decades. This case illustrates the diagnostic odyssey of female DMD patients with complex structural variants that are not detected by current panel or exome sequencing analysis.

Optical genome mapping with genome sequencing identifies subtelomeric Xq28 deletion and inserted 7p22.3 duplication in a male with multisystem developmental disorder

We report a 17-year-old male with supravalvular stenosis, initial failure to thrive and delayed early development, short stature, acromelia, dysmorphic facial features, hypertelorism, macrocephaly, syringomyelia, hypertension, and anxiety disorder. Fluorescent in situ hybridization (FISH), chromosomal microarray analysis (CMA), and exome sequencing (ES) were nondiagnostic. Combined optical genome mapping (OGM) and genome sequencing (GS) showed a complex rearrangement including an X chromosome with a 22.5 kb deletion in band Xq28 replaced by a 61.4 kb insertion of duplicated chromosome 7p22.3 material. The deletion removes the distal 3' untranslated region (UTR) of FUNDC2, the entire CMC4 and MTCP1, and the first five exons of BRCC3. Transcriptome analysis revealed absent expression of CMC4 and MTCP1 and BRCC3 with normal transcript level of FUNDC2. The inserted duplication includes only one known gene: UNCX. Similar overlapping Xq28 deletions have been reported to be associated with Moyamoya disease (MMD), short stature, hypergonadotropic hypogonadism (HH), and facial dysmorphism. Although he has short stature, our patient does not have signs of Moyamoya arteriopathy or hypogonadism. The structurally abnormal X chromosome was present in his mother, but not in his unaffected brother, maternal uncle, or maternal grandparents. We propose that the combination of his absent Xq28 and duplicated 7p22.3 genomic material is responsible for his phenotype. This case highlights the potential of combined OGM and GS for detecting complex structural variants compared with standard of care genetic testing such as CMA and ES.

Exome sequencing confirms the clinical diagnosis of both joubert syndrome and klinefelter syndrome with keratoconus in a han Chinese family

Introduction

Joubert syndrome a rare genetic disorder, is characterized by abnormalities in the development of the central nervous system with "molar signs" on magnetic resonance imaging of the brain and accompanied by cerebellar vermis hypoplasia, ataxia, hypotonia, and developmental delay. Keratoconus (KC) is a kind of genetically predisposed eye disease that causes blindness characterized by a dilated thinning of the central or paracentral cornea conically projected forward, highly irregular astigmatism, and severe visual impairment. Klinefelter syndrome is caused by an extra X chromosome in the cells of male patients, and the main phenotype is tall stature and dysplasia with secondary sex characteristics. This study was intended to identify the genetic etiology and determine the clinical diagnosis of one Han Chinese family with specific clinical manifestations of keratoconus and multiorgan involvement.

Methods

A comprehensive ocular and related general examination was performed on one patient and his asymptomatic parents and brother. Pathogenic genes were tested by exome sequencing. CNV-seq was used to verify the copy number variation, and peripheral blood was cultured for karyotype analysis. The pathogenicity of the identified variant was determined subject to ACMG guidelines. The Gene Expression Omnibus (GEO) dataset of keratoconus-related genes in the NCBI database was obtained to analyze the differentially expressed genes in corneal tissues of the keratoconus group and the normal control group, and analysis of protein-protein interaction networks (PPI) was performed.

Results

Proband, a 25-year-old male, had sudden loss of vision in the left eye for 1 week. Best corrected visual acuity (BCVA): 0.5 (-1.00DS/-5.00DC*29°) in the right eye, counting fingers/40 cm in the left eye. Slit-lamp microscopy of the right eye showed mild anterior protrusion of the cornea and thinning of the cone-topped cornea. The left eye showed marked thinning of the central region of the cornea, rounded edema in the form of a cone-like bulge, epithelial bullae, edema and turbidity of the stroma, and bulging of the Descemet's membrane. Cranial magnetic resonance imaging (MRI) revealed changes in the midbrain and cerebellum, with a "molar sign" and a "bat-winged" ventriculus quartus cerebri. General check-up: 168 cm in height, decreased muscle tone in all four limbs, knee jerk elicited, negative Babinski sign, abdominal reflexes elicited, finger-to-nose test positive, intentional tremor evident in both hands, positive Romberg's sign, instability of gait, level I intellectual disability, poor adaptive behavior, communication disorders, teeth all dentures, a peculiar face with blepharophimosis, wide inner canthus distance, mild ptosis, severe positive epicanthus, high palatal arches, exotropia, hypotrichosis of beard and face, inconspicuous prominentia laryngea, and short upper and lower limbs. Exome sequencing detected compound heterozygous frameshift variants M1:c.9279dup:p.His3094Thrfs*18 and M2:c.6515_6522del:p.Lys2172Thrfs*37 in the patient's CPLANE1 gene and the presence of duplication-type CNV on the X chromosome. Sanger sequencing showed that the mother and father carried the M1 and M2 variants, respectively, and the younger brother carried the M2 variant, which was a novel variant. CNV-seq analysis showed the presence of a duplication-type CNV Xp22.33-Xq28 (2757837-156030895) of approximately 155 Mb on the X chromosome of the proband, which was a de novo variant and carried by neither of the parents. The two heterozygous frameshift variants and duplication-type CNV were pathogenic according to the ACMG guidelines. Differential expression analysis of keratoconus-related genes showed that CPLANE1 was upregulated in the corneal tissues of keratoconus patients compared with normal controls, and such a difference was statistically significant (p = 0.000515, <0.05). PPI analysis showed that the CPLANE1-NPHP3 complex protein acted as a bridge between cilia and extracellular matrix tissue. According to the genetic test results and clinical phenotype analysis, the family was finally diagnosed with Joubert syndrome combined with Keratoconus and Klinefelter syndrome.

Discussion

In this study, we report a proband in a Han Chinese family with both Joubert syndrome and X-linked Klinefelter syndrome as well as keratoconus, and the phenotype spectrum of CPLANE1-Joubert syndrome may be expanded accordingly. Meanwhile, the significance of exome sequencing was emphasized in aiding the clinical diagnosis of complex cases, which is difficult to make.

Copy Number Variation and Epilepsy: State of the Art in the Era of High-Throughput Sequencing-A Multicenter Cohort Study

BACKGROUND

Genetic epilepsy diagnosis is increasing due to technological advancements. Although the use of molecular diagnosis is increasing, chromosomal microarray analysis (CMA) remains an important diagnostic tool for many patients. We aim to explore the role and indications of CMA in epilepsy, given the current genomic advances.

METHODS

We obtained data from 378 epileptic described patients, who underwent CMA between 2015 and 2021. Different types of syndromic or nonsyndromic epilepsy were represented.

RESULTS

After excluding patients who were undertreated or had missing data, we included 250 patients with treated epilepsy and relevant clinical information. These patients mostly had focal epilepsy or developmental and epileptic encephalopathy, with a median start age of 2 years. Ninety percent of the patients had intellectual disability, more than two thirds had normal head size, and 60% had an abnormal magnetic resonance imaging. We also included 10 patients with epilepsy without comorbidities. In our cohort, we identified 35 pathogenic copy number variations (CNVs) explaining epilepsy with nine recurrent CNVs enriched in patients with epilepsy, 12 CNVs related to neurodevelopmental disorder phenotype with possible epilepsy, five CNVs including a gene already known in epilepsy, and nine CNVs based on size combined with de novo occurrence. The diagnosis rate in our study reached 14% (35 of 250) with first-line CMA, as previously reported. Although targeted gene panel sequencing could potentially diagnose some of the reported epilepsy CNVs (34% [12 of 35]).

CONCLUSIONS

CMA remains a viable option as the first-line genetic test in cases where other genetic tests are not available and as a second-line diagnostic technique if gene panel or exome sequencing yields negative results.

Confirmation and pathogenicity of small copy number variations incidentally detected via a targeted next-generation sequencing-based preimplantation genetic testing for aneuploidy platform

OBJECTIVE

To evaluate the technical accuracy, inheritance, and pathogenicity of small copy number variants (CNVs) detected by a targeted next-generation sequencing-based preimplantation genetic testing for aneuploidy (PGT-A) platform.

DESIGN

Retrospective observational study performed between 2020 and 2022.

SETTING

Clinic.

PATIENT(S)

A total of 12,157 patients who underwent clinical PGT-A performed by targeted next-generation sequencing for whole chromosome and large segmental aneuploidies.

INTERVENTION(S)

An incidental finding was reported when a CNV gain/loss of at least 3 consecutive amplicons appeared in at least 2 embryos from the same in vitro fertilization cycle.

MAIN OUTCOME MEASURE(S)

The primary outcome measures were the specificity, incidence, inheritance, and pathogenicity of small CNVs detected by the PGT-A platform. Accuracy of the PGT-A platform CNV calls was assessed via concordance with the CNV calls (size and genomic location) on chromosomal microarray of the gamete provider(s). Parental origin of the CNV and pathogenicity classifications were also reported.

RESULT(S)

An incidental finding that met reporting criteria was identified in 75 (0.62%; 95% confidence interval, 0.5%-0.8%) of 12,157 unique PGT-A patients. Chromosomal microarray follow-up was requested for all cases, and results were received for 1 or both members of 65 reproductive couples. In all cases, 1 of the gamete providers was confirmed to have the CNV identified in the embryos (100.0%, N = 65/65; 95% confidence interval, 94.5-100). The identified CNV was of maternal origin in 34 cases (52.3%) and of paternal origin in 31 cases (47.7%). A significant correlation was identified between PGT-A-predicted CNV sizes and chromosomal microarray detected sizes (r = 0.81) and genomic coordinates on parental deoxyribonucleic acid. Twenty-six (40%) of the CNVs were classified as benign/likely benign, 30 (46.2%) as a variant of uncertain significance, and 9 (13.8%) as pathogenic/likely pathogenic.

CONCLUSION(S)

Certain PGT-A platforms may enable the detection of inherited, small CNVs with extremely high specificity without prior knowledge of parental status. Most CNVs in this data set were confirmed to be benign/likely benign or a variant of uncertain significance. Pathogenic/likely pathogenic CNVs associated with a broad range of phenotypic features may also be detected, although a reliable negative predictive value for small CNVs with current PGT-A technologies is unknown because of the many technical challenges.

Performance of Massive Parallel Sequencing-Based Cell-Free DNA Testing in Compromised Pregnancies

Background/Objectives: Non-Invasive prenatal test (NIPT) is used as a universal or contingent test after prior risk assessment. Screening is mainly performed for common trisomies (T21, T13, T18), although other chromosomal anomalies may be detected. Our objective was to study the performance of GWNIPT in the detection of chromosomal abnormalities in pregnancies in which an invasive prenatal study was performed and in early pregnancy losses, in comparison with the reference test. Method: VeriSeqTM NIPT Solution v2, a genome-wide NIPT (GWNIPT), was performed prior to invasive testing in fetal diagnostic study cases (FDS, n = 155) and in early pregnancy losses (EPL, n = 68). Results: In the FDS group, the diagnostic test (QFPCR, array and karyotype) detected anomalies in 32 pregnancies (21%), in twenty of them (61%) also detected by GWNIPT. Eleven of the twelve cases undetected by GWNIPT were balanced translocations (n = 4) or deletions/duplications <7 Mb (n = 7). In the EPL group, GWNIPT detected anomalies in 46% of cases (31/68) but comparison with reference test (QFPCR and karyotype) in products of conception (POC) was only possible in 18 cases. Concordant results between POC and GWNIPT test were obtained in 16 of the 18 cases. In EPL, with GWNIPT testing, common trisomies accounted for 25.8% of cases (8/31), rare trisomies 54.8% (17/31) and microdeletions/duplications 16.1% (5/31). Conclusions: The GWNIPT test may be useful in clinical practice in prenatal and in EPL's genetic diagnosis when the appropriate sample is not available.

High positive predictive value of CNVs detected by clinical exome sequencing in suspected genetic diseases

BACKGROUND

Genetic disorders often manifest as abnormal fetal or childhood development. Copy number variations (CNVs) represent a significant genetic mechanism underlying such disorders. Despite their importance, the effectiveness of clinical exome sequencing (CES) in detecting CNVs, particularly small ones, remains incompletely understood. We aimed to evaluate the detection of both large and small CNVs using CES in a substantial clinical cohort, including parent-offspring trios and proband only analysis.

METHODS

We conducted a retrospective analysis of CES data from 2428 families, collected from 2018 to 2021. Detected CNV were categorized as large or small, and various validation techniques including chromosome microarray (CMA), Multiplex ligation-dependent probe amplification assay (MLPA), and/or PCR-based methods, were employed for cross-validation.

RESULTS

Our CNV discovery pipeline identified 171 CNV events in 154 cases, resulting in an overall detection rate of 6.3%. Validation was performed on 113 CNVs from 103 cases to assess CES reliability. The overall concordance rate between CES and other validation methods was 88.49% (100/113). Specifically, CES demonstrated complete consistency in detecting large CNV. However, for small CNVs, consistency rates were 81.08% (30/37) for deletions and 73.91% (17/23) for duplications.

CONCLUSION

CES demonstrated high sensitivity and reliability in CNV detection. It emerges as an economical and dependable option for the clinical CNV detection in cases of developmental abnormalities, especially fetal structural abnormalities.

An assessment of the genomic structural variation landscape in Sub-Saharan African populations

Structural variants are responsible for a large part of genomic variation between individuals and play a role in both common and rare diseases. Databases cataloguing structural variants notably do not represent the full spectrum of global diversity, particularly missing information from most African populations. To address this representation gap, we analysed 1,091 high-coverage African genomes, 545 of which are public data sets, and 546 which have been analysed for structural variants for the first time. Variants were called using five different tools and datasets merged and jointly called using SURVIVOR. We identified 67,795 structural variants throughout the genome, with 10,421 genes having at least one variant. Using a conservative overlap in merged data, 6,414 of the structural variants (9.5%) are novel compared to the Database of Genomic Variants. This study contributes to knowledge of the landscape of structural variant diversity in Africa and presents a reliable dataset for potential applications in population genetics and health-related research.

REEV: review, evaluate and explain variants

In the era of high throughput sequencing, special software is required for the clinical evaluation of genetic variants. We developed REEV (Review, Evaluate and Explain Variants), a user-friendly platform for clinicians and researchers in the field of rare disease genetics. Supporting data was aggregated from public data sources. We compared REEV with seven other tools for clinical variant evaluation. REEV (semi-)automatically fills individual ACMG criteria facilitating variant interpretation. REEV can store disease and phenotype data related to a case to use these for phenotype similarity measures. Users can create public permanent links for individual variants that can be saved as browser bookmarks and shared. REEV may help in the fast diagnostic assessment of genetic variants in a clinical as well as in a research context. REEV (https://reev.bihealth.org/) is free and open to all users and there is no login requirement.

Case report: An adolescent female with anosmic hypogonadotropic hypogonadism, intellectual disability, and papillary thyroid carcinoma: heterozygous deletion of TCF12

Background

Isolated hypogonadotropic hypogonadism is a heterogeneous clinical entity. There is a growing list of molecular defects that are associated with hypogonadotropic hypogonadism (HH). TCF12, a recently identified molecular defect, causes craniosynostosis and is suggested to be used as a biomarker for prognosis in various cancer types. Recently, TCF12 variants were shown in a cohort with HH.

Case presentation

A 15.3 years old female patient was referred to the endocrinology clinic for obesity. She had been gaining weight from mid-childhood. She had her first epileptic seizure at the age of 15.1 years and mildly elevated thyroid autoantibodies were detected during evaluation for etiology of seizures. She had not experienced menarche yet. She was operated for left strabismus at the age of 7 years. School performance was poor and she was receiving special education. Tanner stage of breast was 1 and pubic hair was 3. The endocrine workup revealed hypogonadotropic hypogonadism. Also, the Sniffin' Sticks test detected anosmia. Thyroid ultrasonography was performed due to the mildly elevated thyroid autoantibodies, and thyroid nodules with punctate calcifications were detected. Total thyroidectomy and central lymph node dissection were performed regarding the cytological findings of the nodules and multicentric papillary thyroid carcinoma with no lymph node metastasis was detected on pathology specimens. Regarding the phenotypic features of the patients, whole exome sequencing was performed and heterozygous deletion of exon 1 and exon 6-8 in TCF12 was detected.

Conclusion

Haploinsufficiency of TCF12 causes anosmic HH. Probably due to the incomplete penetrance and variable expressivity of the disease, patients could display variable phenotypic features such as intellectual disability, developmental delay, and craniosynostosis. Further description of new cases with TCF12 variations could enhance our understanding of craniosynostosis and its potential link to Kallmann syndrome associated with this gene.

First copy number variant in trans with single nucleotide variant in CCN6 causing progressive pseudorheumatoid dysplasia revealed by genome sequencing and deep phenotyping in monozygotic twins

Biallelic pathogenic variants in CCN6 cause progressive pseudorheumatoid dysplasia (PPD), a rare skeletal dysplasia. The predominant features include noninflammatory progressive joint stiffness and enlargement, which are not unique to this condition. Nearly 100% of the reported variants are single nucleotide variants or small indels, and missing of a second variant has been reported. Genome sequencing (GS) covers various types of variants and deep phenotyping (DP) provides detailed and precise information facilitating genetic data interpretation. The combination of GS and DP improves diagnostic yield, especially in rare and undiagnosed diseases. We identified a novel compound heterozygote involving a disease-causing copy number variant (g.112057664_112064205del) in trans with a single nucleotide variant (c.624dup(p.Cys209MetfsTer21)) in CCN6 in a pair of monozygotic twins, through the methods of GS and DP. The twins had received three nondiagnostic results before. The g.112057664_112064205del variant was missed by all the tests, and the recorded phenotypes were inaccurate or even misleading. The twins were diagnosed with PPD, ending a 13-year diagnostic odyssey. There may be other patients with PPD experiencing underdiagnosis and misdiagnosis due to inadequate genetic testing or phenotyping methods. This case highlights the critical role of GS and DP in facilitating an accurate and timely diagnosis.

Silver-Russell syndrome-like features in a child with recombinant chromosome 11 derived from maternal pericentric inversion

Silver-Russell syndrome (SRS) is a well-known syndrome but with heterogeneous etiologies. We present the case of a child with severe SRS-like features resulting from a complex rearrangement of chromosome 11 inherited from his mother. We studied the index case with karyotyping, MS-MLPA and molecular karyotyping. The mother was studied with karyotyping and subtelomeric FISH. We found a child with marked developmental delay and fatal outcome due to failure to thrive, carrying an 11p15 duplication and an 11q25 deletion of maternal origin. We discovered that the mother was a carrier of a pericentric inversion of chromosome 11, with a history of recurrence in other family members who had severe growth retardation and early death. To our knowledge, no similar SRS-like cases have been described in the literature. This report supports the importance of identification the causative genetic mechanism in SRS-like individuals with duplication in 11p15 region due to high risk of recurrence and to provide an appropriate genetic counseling to the family.

Concurrent of compound heterozygous variant of a novel in-frame deletion and the common hypomorphic haplotype in TBX6 and inherited 17q12 microdeletion in a fetus

BACKGROUND

TBX6, a member of the T-box gene family, encodes the transcription factor box 6 that is critical for somite segmentation in vertebrates. It is known that the compound heterozygosity of disruptive variants in trans with a common hypomorphic risk haplotype (T-C-A) in the TBX6 gene contribute to 10% of congenital scoliosis (CS) cases. The deletion of chromosome 17q12 is a rare cytogenetic abnormality, which often leads to renal cysts and diabetes mellitus. However, the affected individuals often exhibit clinical heterogeneity and incomplete penetrance.

METHODS

We here present a Chinese fetus who was shown to have CS by ultrasound examination at 17 weeks of gestation. Trio whole-exome sequencing (WES) was performed to investigate the underlying genetic defects of the fetus. In vitro functional experiments, including western-blotting and luciferase transactivation assay, were performed to determine the pathogenicity of the novel variant of TBX6.

RESULTS

WES revealed the fetus harbored a compound heterozygous variant of c.338_340del (p.Ile113del) and the common hypomorphic risk haplotype of the TBX6 gene. In vitro functional study showed the p.Ile113del variant had no impact on TBX6 expression, but almost led to complete loss of its transcriptional activity. In addition, we identified a 1.85 Mb deletion on 17q12 region in the fetus and the mother. Though there is currently no clinical phenotype associated with this copy number variation in the fetus, it can explain multiple renal cysts in the pregnant woman.

CONCLUSIONS

This study is the first to report a Chinese fetus with a single amino acid deletion variant and a T-C-A haplotype of TBX6. The clinical heterogeneity of 17q12 microdeletion poses significant challenges for prenatal genetic counseling. Our results once again suggest the complexity of prenatal genetic diagnosis.

Exome sequencing (ES) of a pediatric cohort with chronic endocrine diseases: a single-center study (within the framework of the TRANSLATE-NAMSE project)

BACKGROUND

Endocrine disorders are heterogeneous and include a significant number of rare monogenic diseases.

METHODS

We performed exome sequencing (ES) in 106 children recruited from a single center within the TRANSLATE‑NAMSE project. They were categorized into subgroups: proportionate short stature (PSS), disproportionate short stature (DSS), hypopituitarism (H), differences in sexual development (DSD), syndromic diseases (SD) and others.

RESULTS

The overall diagnostic yield was 34.9% (n = 37/106), including 5 patients with variants in candidate genes, which have contributed to collaborations to identify gene-disease associations. The diagnostic yield varied significantly between subgroups: PSS: 16.6% (1/6); DSS: 18.8% (3/16); H: 17.1% (6/35); DSD: 37.5% (3/8); SD: 66.6% (22/33); others: 25% (2/8). Confirmed diagnoses included 75% ultrarare diseases. Three patients harbored more than one disease-causing variant, resulting in dual diagnoses.

CONCLUSIONS

ES is an effective tool for genetic diagnosis in pediatric patients with complex endocrine diseases. An accurate phenotypic description, including comprehensive endocrine diagnostics, as well as the evaluation of variants in multidisciplinary case conferences involving geneticists, are necessary for personalized diagnostic care. Here, we illustrate the broad spectrum of genetic endocrinopathies that have led to the initiation of specific treatment, surveillance, and family counseling.

Clinical and genetic characteristics in a Chinese cohort of complex spastic paraplegia type 4

Spastic paraplegia type 4 (SPG4), caused by SPAST mutations, is the most predominant subtype of hereditary spastic paraplegia. Most documented SPG4 patients present as pure form, with the complex form rarely reported. We described the clinical and genetic features of 20 patients with complex phenotypes of SPG4 and further explored the genotype-phenotype correlations. We collected detailed clinical data of all SPG4 patients and assessed their phenotypes. SPAST gene mutations were identified by Multiplex ligation-dependent probe amplification in combination with whole exome sequencing. We further performed statistical analysis in genotype and phenotype among patients with various manifestations and different variants. Out of 90 SPG4 patients, 20 patients (male:female = 16:4) with additional neurologic deficits, namely complex form, were included in our study. The bimodal distribution of age of onset at 0-10 and 21-40 years old is concluded. On cranial MRI, obvious white matter lesions can be observed in five patients. We identified 9 novel and 8 reported SPAST mutations, of which 11 mutations were located in AAA (ATPase associated with various cellular activities) domain. The AAA cassette of spastin is the hottest mutated region among complex SPG4. All patients with cognitive impairment (CI) are males (n = 9/9). Additionally, 80% patients with ataxia are due to frameshift mutations (n = 4/5). Overall, our study summarized and analyzed the genetic and phenotypic characteristics of complex SPG4, making up over 1/5 of in-house SPG4 cohort, among which CI and ataxia are the most common features. Further studies are expected to explore the underlying mechanisms.

The role of genomic disorders in chronic kidney failure of undetermined aetiology ≤50 years

Background

Genomic disorders caused by copy number variations (CNVs) are prevalent in patients with kidney disease; however, their contribution to chronic kidney failure (KF) of undetermined aetiology (uKF) is unclear. We screened patients with uKF aged 50 years or younger to establish the prevalence of causative CNVs.

Methods

We enrolled patients with an onset of KF ≤50 years from suspected undetermined aetiology for initial review of medical records to exclude patients with clear-cut clinical or histopathological kidney diagnoses or patients with already established genetic kidney diseases. Next, we performed single nucleotide polymorphism (SNP) array-based CNV screening. All the detected CNVs were systematically classified and evaluated as possible causes of the patient's kidney disease. Patients with CNVs not explaining the kidney phenotype were additionally screened for causal variants in 540 genes using whole-genome sequencing.

Results

We enrolled 172 patients, of whom 123 underwent SNP-array. Pathogenic CNVs corresponding to known genomic disorders were identified in 12 patients (9.8%). The identified genomic disorders provided a causative kidney diagnosis in three patients, all of whom had reached KF by age 18 years. The remaining nine patients had CNVs with unclear kidney disease causality. Subsequently, whole-genome sequencing provided a causative genetic diagnosis in an additional four patients, including two diagnostic sequence variants unrelated to the detected CNVs.

Conclusions

Genomic disorders were prevalent in this cohort with uKF, and causative CNVs were identified in 5 of 123 patients. Further studies combining the analysis of CNVs and sequence variants are needed to clarify the causal role of genomic disorders in kidney disease.

Expanding the phenotypic spectrum of NOTCH1 variants: clinical manifestations in families with congenital heart disease

Pathogenic variants in NOTCH1 are associated with non-syndromic congenital heart disease (CHD) and Adams-Oliver syndrome (AOS). The clinical presentation of individuals with damaging NOTCH1 variants is characterized by variable expressivity and incomplete penetrance; however, data on systematic phenotypic characterization are limited. We report the genotype and phenotype of a cohort of 33 individuals (20 females, 13 males; median age 23.4 years, range 2.5-68.3 years) from 11 families with causative NOTCH1 variants (9 inherited, 2 de novo; 9 novel), ascertained from a proband with CHD. We describe the cardiac and extracardiac anomalies identified in these 33 individuals, only four of whom met criteria for AOS. The most common CHD identified was tetralogy of Fallot, though various left- and right-sided lesions and septal defects were also present. Extracardiac anomalies identified include cutis aplasia (5/33), cutaneous vascular anomalies (7/33), vascular anomalies of the central nervous system (2/10), Poland anomaly (1/33), pulmonary hypertension (2/33), and structural brain anomalies (3/14). Identification of these findings in a cardiac proband cohort supports NOTCH1-associated CHD and NOTCH1-associated AOS lying on a phenotypic continuum. Our findings also support (1) Broad indications for NOTCH1 molecular testing (any familial CHD, simplex tetralogy of Fallot or hypoplastic left heart); (2) Cascade testing in all at-risk relatives; and (3) A thorough physical exam, in addition to cardiac, brain (structural and vascular), abdominal, and ophthalmologic imaging, in all gene-positive individuals. This information is important for guiding the medical management of these individuals, particularly given the high prevalence of NOTCH1 variants in the CHD population.

Refugee and asylum-seeker children and health problems in the city of Duzce, Türkiye

INTRODUCTION

This study examines the health problems and healthcare needs of refugee and asylum-seeker children and aims to develop strategies for improvement.

METHODS

Based on quantitative data from 448 refugee and asylum-seeker children and 222 non-refugee local children, this study was conducted at Düzce University, Department of Paediatrics, between 2010 and 2021. The refugee children originated from three countries: Iraq (n = 304), Syria (n = 101) and Afghanistan (n = 43). The data were analysed using the SPSS data analysis program. Ethical clearance was obtained from the Ethics Committee of Düzce Üniversity.

RESULTS

The results suggest that refugee and asylum-seeker children have significantly higher rates of acute illness or infection, malnutrition (p < 0.001) and anaemia (p < 0.001) than local children as a result of living in overcrowded families (p = 0.017) and unhealthy conditions. Adolescent pregnancy (p = 0.049) emerges as an important social problem as a result of child marriage among refugee children, mostly in the form of consanguineous marriages (p < 0.001). The rate of having at least two adolescent pregnancies (under 18) was highest among Syrian refugee girls (p = 0.01). Although refugee and asylum-seeker children have higher rates of health insurance (between 74% and 95%), they have lower rates of insurance compared to local children. This research also compares the data from three nationalities, including Syria, Afghanistan and Iraq children; Iraqi and Afghan children under the international protection (IP) system with limited social support and rights had worse health conditions compared to other groups. Although Iraqi children had the highest rates of health insurance on admission (p < 0.001), they also had higher rates of chronic diseases (p = 0.001), infections (p = 0.004), allergic rhinitis (p = 0.001) and malnutrition (p < 0.001). The youngest age of admission (p = 0.006) and the shortest length of stay (p = 0.004) were for Afghan children who also had higher rates of upper respiratory infections (p = 0.021).

CONCLUSIONS

This study highlights the urgent need for improved screening programmes and the importance of collaborative efforts to address the specific health needs of these populations. Addressing the health status of child refugees is a complex and multifaceted task that requires the active participation of healthcare professionals, policymakers and researchers, each of whom has a crucial role to play.

Comparison of the ABC and ACMG systems for variant classification

The ABC and ACMG variant classification systems were compared by asking mainly European clinical laboratories to classify variants in 10 challenging cases using both systems, and to state if the variant in question would be reported as a relevant result or not as a measure of clinical utility. In contrast to the ABC system, the ACMG system was not made to guide variant reporting but to determine the likelihood of pathogenicity. Nevertheless, this comparison is justified since the ACMG class determines variant reporting in many laboratories. Forty-three laboratories participated in the survey. In seven cases, the classification system used did not influence the reporting likelihood when variants labeled as "maybe report" after ACMG-based classification were included. In three cases of population frequent but disease-associated variants, there was a difference in favor of reporting after ABC classification. A possible reason is that ABC step C (standard variant comments) allows a variant to be reported in one clinical setting but not another, e.g., based on Bayesian-based likelihood calculation of clinical relevance. Finally, the selection of ACMG criteria was compared between 36 laboratories. When excluding criteria used by less than four laboratories (<10%), the average concordance rate was 46%. Taken together, ABC-based classification is more clear-cut than ACMG-based classification since molecular and clinical information is handled separately, and variant reporting can be adapted to the clinical question and phenotype. Furthermore, variants do not get a clinically inappropriate label, like pathogenic when not pathogenic in a clinical context, or variant of unknown significance when the significance is known.

Accuracy of expanded noninvasive prenatal testing for maternal copy number variations: A comparative study with CNV-seq of maternal lymphocyte DNA

OBJECTIVE

To evaluate the accuracy of expanded noninvasive prenatal testing (NIPT) for maternal copy number variations.

MATERIALS AND METHODS

Expanded NIPT was used to detect CNVs ≥2 Mb at a whole-genome scale. The threshold of maternal deletion was copy numbers (CN) ≤ 1.6, and the threshold of maternal duplication was CN ≥ 2.4.

RESULTS

Of the 5440 pregnant women with successful expanded NIPT results, 28 maternal CNVs ≥2 Mb were detected in 27 pregnant women. Except for five cases reported as test failure, 23 CNVs ≥2 Mb were confirmed among the remaining 22 pregnant women by CNV-seq of maternal lymphocyte DNA. The genomic location, copy numbers and fragment size of maternal CNVs reported by expanded NIPT were consistent with the results of CNV-seq of maternal lymphocyte DNA.

CONCLUSIONS

Maternal CNVs ≥2 Mb can be accurately evaluated according to the CN indicated by expanded NIPT results.