First case report of dichorionic diamniotic twins with chronic enteropathy associated with the SLCO2A1 gene

We report the case of twins diagnosed with chronic enteropathy associated with the SLCO2A1 gene (CEAS) based on characteristic ulcer findings, which required 8 years to diagnose. Both twins had similar symptoms, including anemia and growth failure but the gastrointestinal tract was not evaluated initially because of mild symptoms that were considered consistent with psychological etiology. The endoscopic findings of the firstborn child showed spiral ulcer scars and pseudodiverticulum formation without Helicobacter pylori infection or eosinophilic infiltration in the duodenum. Since the twins presented with ulcers of an unknown cause simultaneously and the first-born child had a spiral ulcer, CEAS was suspected. Genetic analysis and high levels of prostaglandin E major urinary metabolites in the urine led to a definitive diagnosis of CEAS.

Combining preoperative C-reactive protein values with the Tokyo Guidelines 2018 grading criteria can enhance the prediction of surgical difficulty in early laparoscopic cholecystectomy for acute cholecystitis

BACKGROUND

Early laparoscopic cholecystectomy (ELC) is the standard treatment for acute cholecystitis (AC). However, predicting the difficulty of this procedure remains challenging. The present study aimed to develop an improved prediction model for surgical difficulty during ELC, surpassing the current Tokyo Guidelines 2018 (TG18) grading system.

METHODS

We analyzed data from 201 consecutive patients who underwent ELC for AC between 2019 and 2021. Surgical difficulty was defined as the failure to achieve the critical view of safety (non-CVS). We developed a scoring system by conducting multivariate analysis on demographics, symptoms, laboratory data, and radiographic findings. The predictive accuracy of our scoring system was compared to that of the TG18 grading system (Grade I vs. Grade II/III).

RESULTS

Through multivariate logistic regression analysis, a novel scoring system was formulated. This system incorporated preoperative C-reactive protein (CRP) values (≥5: 1 pt, ≥10: 2 pts, ≥15: 3 pts) and TG18 grading score (duration >72 h: 1 pt, image criteria for Grade II AC: 1 pt). Our model, a cutoff score of ≥3, exhibited a significantly elevated area under the curve (AUC) of 0.721 compared to the TG18 grading system alone (AUC 0.609) (p = 0.001).

CONCLUSION

Combining preoperative CRP values with TG18 grading criteria can enhance the accuracy of predicting intraoperative difficulty in ELC for AC.

Genetic backgrounds and genotype-phenotype relationships in anthropometric parameters of 116 Japanese individuals with Noonan syndrome

Noonan syndrome (NS) is caused by pathogenic variants in genes encoding components of the RAS/MAPK pathway and presents with a number of symptoms, including characteristic facial features, congenital heart diseases, and short stature. Advances in genetic analyses have contributed to the identification of pathogenic genes in NS as well as genotype-phenotype relationships; however, updated evidence for the detection rate of pathogenic genes with the inclusion of newly identified genes is lacking in Japan. Accordingly, we examined the genetic background of 116 individuals clinically diagnosed with NS and the frequency of short stature. We also investigated genotype-phenotype relationships in the context of body mass index (BMI). Genetic testing revealed the responsible variants in 100 individuals (86%), where PTPN11 variants were the most prevalent (43%) and followed by SOS1 (12%) and RIT1 (9%). The frequency of short stature was the lowest in subjects possessing RIT1 variants. No genotype-phenotype relationships in BMI were observed among the genotypes. In conclusion, this study provides evidence for the detection rate of pathogenic genes and genotype-phenotype relationships in Japanese patients with NS, which will be of clinical importance for accelerating our understanding of the genetic backgrounds of Japanese patients with NS.

Abnormal axonal development and severe epileptic phenotype in Dynamin-1 (DNM1) encephalopathy

Dynamin-1 (DNM1) is involved in synaptic vesicle recycling, and DNM1 mutations can lead to developmental and epileptic encephalopathy. The neuroimaging of DNM1 encephalopathy has not been reported in detail. We describe a severe phenotype of DNM1 encephalopathy showing characteristic neuroradiological features. In addition, we reviewed previously reported cases who have DNM1 pathogenic variants with white matter abnormalities. Our case presented drug-resistant seizures from 1 month of age and epileptic spasms at 2 years of age. Brain MRI showed no progression of myelination, progression of diffuse cerebral atrophy, and a thin corpus callosum. Proton magnetic resonance spectroscopy showed a decreased N-acetylaspartate peak and diffusion tensor imaging presented with less pyramidal decussation. Whole-exome sequencing revealed a recurrent de novo heterozygous variant of DNM1. So far, more than 50 cases of DNM1 encephalopathy have been reported. Among these patients, delayed myelination occurred in two cases of GTPase-domain DNM1 encephalopathy and in six cases of middle-domain DNM1 encephalopathy. The neuroimaging findings in this case suggest inadequate axonal development. DNM1 is involved in the release of synaptic vesicles with the inhibitory transmitter GABA, suggesting that GABAergic neuron dysfunction is the mechanism of refractory epilepsy in DNM1 encephalopathy. GABA-mediated signaling mechanisms play important roles in axonal development and GABAergic neuron dysfunction may be cause of white matter abnormalities in DNM1 encephalopathy.

Clinical details of individuals with Rauch-Steindl syndrome due to NSD2 truncating variants

BACKGROUND

Rauch-Steindl syndrome (RAUST) is a very rare genetic syndrome caused by a pathogenic variant in NSD2 on chromosome 4p16.3. Although NSD2 was previously thought to be the major gene in Wolf-Hirschhorn syndrome (WHS), a contiguous gene syndrome of chromosome 4p16.3 deletion, RAUST has been found to present different facial and clinical features from WHS. In this study, we report the details of two newly diagnosed individuals with RAUST in order to better understand the molecular and clinical features of RAUST.

METHODS

Whole-genome sequencing was performed on two individuals with psychomotor delay and growth failure. Detailed clinical evaluation of growth parameters, craniofacial features, electroencephalogram (EEG), magnetic resonance imaging of the brain, and developmental assessment were performed.

RESULTS

Both individuals had de novo truncating variants in NSD2. One had a novel variant (c.2470C>T, p.Arg824*), and the other had a recurrent variant (c.4028del, p.Pro1343Glnfs*49). Both exhibited characteristic RAUST facial features, growth failure, and mild psychomotor delay. A novel finding of RAUST was seen in individual 2, a Chiari malformation type 1, and both showed delayed bone age. They lacked common WHS features such as congenital heart defects, cleft lip/palate, and seizures (EEG with abnormal findings).

CONCLUSION

We present a novel variant and clinical presentations of RAUST, expand the molecular and clinical diversity of RAUST, and improve our understanding of this rare syndrome, which is distinct from WHS. Further researches are needed on more RAUST cases and on functional analysis of NSD2.

Craniosynostosis in molecularly diagnosed Kabuki syndrome: Prevalence and clinical implications

Kabuki syndrome (KS) is characterized by growth impairment, psychomotor delay, congenital heart disease, and distinctive facial features. KMT2D and KDM6A have been identified as the causative genes of KS. Craniosynostosis (CS) has been reported in individuals with KS; however, its prevalence and clinical implications remain unclear. In this retrospective study, we investigated the occurrence of CS in individuals with genetically diagnosed KS and examined its clinical significance. Among 42 individuals with genetically diagnosed KS, 21 (50%) exhibited CS, with 10 individuals requiring cranioplasty. No significant differences were observed based on sex, causative gene, and molecular consequence among individuals with KS who exhibited CS. Both individuals who underwent evaluation with three-dimensional computed tomography (3DCT) and those who required surgery tended to exhibit cranial dysmorphology. Notably, in several individuals, CS was diagnosed before KS, suggesting that CS could be one of the clinical features by which clinicians can diagnose KS. This study highlights that CS is one of the noteworthy complications in KS, emphasizing the importance of monitoring cranial deformities in the health management of individuals with KS. The findings suggest that in individuals where CS is a concern, conducting 3DCT evaluations for CS and digital impressions are crucial.

Haploinsufficiency of NKX2-1 is likely to contribute to developmental delay involving 14q13 microdeletions

Nucleotide variations or deletions in the NK2 homeobox 1 gene (NKX2-1), located at 14q13.3, lead to symptoms associated with the brain, lungs, and thyroid, and the combination of these phenotypes is clinically recognized as the brain-lung-thyroid syndrome. Many types of nucleotide variants of NKX2-1 have been identified, and phenotypic variability has been reported. Chromosomal deletions involving NKX2-1 have also been reported; however, phenotypic differences between patients with nucleotide variants of NKX2-1 and patients with chromosomal deletions involving NKX2-1 have not been well established. Recently, we identified seven patients with 14q13 microdeletions involving the NKX2-1. Most patients exhibited developmental delay. This inquiry arises regarding the potential existence of haploinsufficiency effects beyond those attributed to NKX2-1 within the 14q13 microdeletion. However, a literature review has shown that developmental delay is not rare in patients with nucleotide alterations in NKX2-1. Rather, motor function impairment may have affected the total developmental assessment, and the haploinsufficiency of genes contiguous to NKX2-1 is unlikely to contribute to developmental delay.

A heterozygous germline deletion within USP8 causes severe neurodevelopmental delay with multiorgan abnormalities

Ubiquitin-specific protease 8 (USP8) is a deubiquitinating enzyme involved in deubiquitinating the enhanced epidermal growth factor receptor for escape from degradation. Somatic variants at a hotspot in USP8 are a cause of Cushing's disease, and a de novo germline USP8 variant at this hotspot has been described only once previously, in a girl with Cushing's disease and developmental delay. In this study, we investigated an exome-negative patient with severe developmental delay, dysmorphic features, and multiorgan dysfunction by long-read sequencing, and identified a 22-kb de novo germline deletion within USP8 (chr15:50469966-50491995 [GRCh38]). The deletion involved the variant hotspot, one rhodanese domain, and two SH3 binding motifs, and was presumed to be generated through nonallelic homologous recombination through Alu elements. Thus, the patient may have perturbation of the endosomal sorting system and mitochondrial autophagy through the USP8 defect. This is the second reported case of a germline variant in USP8.

Progressive myoclonic epilepsy as an expanding phenotype of NGLY1-associated congenital deglycosylation disorder: A case report and review of the literature

INTRODUCTION

NGLY1-associated congenital disorder of deglycosylation (CDDG1: OMIM #615273) is a rare autosomal recessive disorder caused by a functional impairment of endoplasmic reticulum in degradation of glycoproteins. Neurocognitive dysfunctions have been documented in patients with CDDG1; however, deteriorating phenotypes of affected individuals remain elusive.

CASE PRESENTATION

A Japanese boy with delayed psychomotor development showed ataxic movements from age 5 years and myoclonic seizures from age 12 years. Appetite loss, motor and cognitive decline became evident at age 12 years. Electrophysiological studies identified paroxysmal discharges on myoclonic seizure and a giant somatosensory evoked potential. Perampanel was effective for controlling myoclonic seizures. Exome sequencing revealed that the patient carried compound heterozygous variants in NGLY1, NM_018297.4: c.857G > A and c.-17_12del, which were inherited from mother and father, respectively. A literature review confirmed that myoclonic seizures were observed in 28.5% of patients with epilepsy. No other patients had progressive myoclonic epilepsy or cognitive decline in association with loss-of-function variations in NGLY1.

CONCLUSION

Our data provides evidence that a group of patients with CDDG1 manifest slowly progressive myoclonic epilepsy and cognitive decline during the long-term clinical course.

A novel DLG4 variant causes DLG4-related synaptopathy with intellectual regression

DLG4-related synaptopathy is a neurodevelopmental disorder caused by a DLG4 variant. We identified a novel de novo heterozygous frameshift variant, NM_001321075.3(DLG4):c.554_563del, in a Japanese girl. Intellectual regression without motor delay was observed at 2 years of age, and she was diagnosed with autism spectrum disorder and attention-deficit/hyperactivity disorder. Recognizing the possibility of DLG4-related synaptopathy in patients with intellectual regression is important for ensuring an accurate diagnosis.

Safety and short-term outcomes of robotic-assisted transabdominal preperitoneal repair for inguinal hernia in pioneering hospitals in Japan: A nationwide retrospective cohort study

INTRODUCTION

We aimed to evaluate the safety and short-term outcomes of robotic-assisted transabdominal preperitoneal repair for inguinal hernia in 12 pioneering hospitals in Japan.

METHODS

Clinical data of patients who underwent robotic-assisted transabdominal preperitoneal repair between September 1, 2016, and December 31, 2021 were collected. Primary outcome measures were intra-operative adverse events and post-operative complications, whereas secondary outcomes were surgical outcomes, including chronic pain, recurrence, and learning curve.

RESULTS

In total, 307 patients were included. One case of inferior epigastric arterial injury was reported; no cases of bowel or bladder injury were reported. Thirty-five seromas were observed, including four (1.3%) cases that required aspiration. The median operative time of a unilateral case was 108 minutes (interquartile range: 89.8-125.5), and post-operative pain was rated 1 (interquartile range: 0-2) on the numerical rating scale. In complicated cases, such as recurrent inguinal hernias and robotic-assisted radical prostatectomy-associated hernias, dissection and suture were safely achieved, and no complications were observed, except for non-symptomatic seroma. All patients underwent robotic procedures, and there was no chronic post-operative inguinal pain, although one case of hernia recurrence was reported. Regarding the learning curve, plateau performance was achieved after 7-10 cases in terms of operative time (P < .001).

CONCLUSION

Robotic-assisted transabdominal preperitoneal repair can be safely introduced in Japan. Regardless of the involvement of many surgeons, the mastery of robotic techniques was achieved relatively quickly. The advantage of robotic technology such as wristed instruments may expand the application of minimally invasive hernia repair for complicated cases.

Modelling Takenouchi-Kosaki syndrome using disease-specific iPSCs

Takenouchi-Kosaki Syndrome (TKS) is a congenital multi-organ disorder caused by the de novo missense mutation c.191A > G p. Tyr64Cys (Y64C) in the CDC42 gene. We previously elucidated the functional abnormalities and thrombopoietic effects of Y64C using HEK293 and MEG01 cells. In the present study, we used iPSCs derived from TKS patients to model the disease and successfully recapitulated macrothrombocytopenia, a prominent TKS phenotype. The megakaryopoietic differentiation potential of TKS-iPSCs and platelet production capacity were examined using an efficient platelet production method redesigned from existing protocols. The results obtained showed that TKS-iPSCs produced fewer hematopoietic progenitor cells, exhibited defective megakaryopoiesis, and released platelets with an abnormally low count and giant morphology. We herein report the first analysis of TKS-iPSC-derived megakaryocytes and platelets, and currently utilize this model to perform drug evaluations for TKS. Therefore, our simple yet effective differentiation method, which mimics the disease in a dish, is a feasible strategy for studying hematopoiesis and related diseases.

Identification of small-sized intrachromosomal segments at the ends of INV-DUP-DEL patterns

The mechanism of chromosomal rearrangement associated with inverted-duplication-deletion (INV-DUP-DEL) pattern formation has been investigated by many researchers, and several possible mechanisms have been proposed. Currently, fold-back and subsequent dicentric chromosome formation has been established as non-recurrent INV-DUP-DEL pattern formation mechanisms. In the present study, we analyzed the breakpoint junctions of INV-DUP-DEL patterns in five patients using long-read whole-genome sequencing and detected 2.2-6.1 kb copy-neutral regions in all five patients. At the end of the INV-DUP-DEL, two patients exhibited chromosomal translocations, which are recognized as telomere capture, and one patient showed direct telomere healing. The remaining two patients had additional small-sized intrachromosomal segments at the end of the derivative chromosomes. These findings have not been previously reported but they may only be explained by the presence of telomere capture breakage. Further investigations are required to better understand the mechanisms underlying this finding.

Time required for indocyanine green fluorescence emission for evaluating bowel perfusion in left-sided colon and rectal cancer surgery

BACKGROUND

Indocyanine green fluorescence imaging (ICG-FI) has been reported to be useful in reducing the incidence of anastomotic leakage (AL) in colectomy. This study aimed to investigate the correlation between the required time for ICG fluorescence emission and AL in left-sided colon and rectal cancer surgery using the double-stapling technique (DST) anastomosis.

METHODS

This retrospective study included 217 patients with colorectal cancer who underwent left-sided colon and rectal surgery using ICG-FI-based perfusion assessment at our department between November 2018 and July 2022. We recorded the time required to achieve maximum fluorescence emission after ICG systemic injection and assessed its correlation with the occurrence of AL.

RESULTS

Among 217 patients, AL occurred in 21 patients (9.7%). The median time from ICG administration to maximum fluorescence emission was 32 s (range 25-58 s) in the AL group and 28 s (range 10-45 s) in the non-AL group (p < 0.001). The cut-off value for the presence of AL obtained from the ROC curve was 31 s. In 58 patients with a required time for ICG fluorescence of 31 s or longer, the following risk factors for AL were identified: low preoperative albumin [3.4 mg/dl (range 2.6-4.4) vs. 3.9 mg/dl (range 2.6-4.9), p = 0.016], absence of preoperative mechanical bowel preparation (53.8% vs. 91.1%, p = 0.005), obstructive tumor (61.5% vs. 17.8%, p = 0.004), and larger tumor diameter [65 mm (range 40-90) vs. 35 mm (range 4.0-100), p < 0.001].

CONCLUSION

The time required for ICG fluorescence emission was associated with AL.

Comparison of short-term outcomes of robotic and laparoscopic transabdominal peritoneal repair for unilateral inguinal hernia: a propensity-score matched analysis

PURPOSE

This study aimed to compare perioperative outcomes of robotic and laparoscopic transabdominal peritoneal repair (TAPP) for unilateral inguinal hernia.

METHODS

This single institutional retrospective cohort study used de-identified data of patients who underwent robotic TAPP (R-TAPP) or laparoscopic TAPP (L-TAPP) for unilateral inguinal hernia between January 1, 2016 and October 31, 2021. Two cohorts were propensity matched, and data were analyzed. The learning curve was evaluated in the R-TAPP group.

RESULTS

Among 938 patients analyzed, 704 were included. After propensity-score matching, 80 patients were included in each group. The difference in operative time between R-TAPP and L-TAPP groups was 10 min (99.5 and 89.5 min, p = 0.087); however, console/laparoscopic time was similar (67 and 66 min, p = 0.71). The dissection time for medial-type hernia in the R-TAPP group was marginally shorter than that in the L-TAPP group (17 and 27 min, p = 0.056); however, there was no difference for lateral-type hernia (38.5 and 40 min p = 0.37). Perioperative variables, including estimated blood loss, postoperative hospital stay, and postoperative pain, had no significant difference, and chronic pain, which needed medication or intervention, was not observed in each group. The number of cases needed to achieve plateau performance was 7-10 in the R-TAPP group.

CONCLUSION

This study suggests that R-TAPP was safely introduced, and its perioperative outcomes were not inferior to those of L-TAPP. A shorter dissection time for medial-type hernia might be due to the robot's advantages, and a fast-learning curve could help with the early standardization of the procedure.

Triple repeated fetal congenital heart disease linked to PLD1 mutation: a case report

BACKGROUND

Congenital heart disease occurs in approximately 1 in 100 cases. Although sibling occurrence is high (3-9%), the causative genes for this disease are still being elucidated. PLD1 (Phospholipase D1) is a recently discovered gene; however, few case reports have been published on it. In this report, we describe a case of triplicate fetal congenital heart disease that was diagnosed as a PDL1 mutation. Our objective is to explore the clinical manifestations of PLD1 mutations in this particular case.

CASE PRESENTATION

A 32-year-old Japanese woman (gravida, para 0) was introduced since fetus four chamber view was not clear and was diagnosed with ductus arteriosus-dependent left ventricular single ventricle and pulmonary atresia at 21 weeks and 1 day of gestation during her first pregnancy. Artificial abortion using Gemeprost was performed at 21 weeks and 5 days of gestation. The second pregnancy was diagnosed as pulmonary atresia with intact ventricular septum with cardiomegaly, a cardiothoracic area ratio of more than 35%, and a circulatory shunt at 13 weeks and 3 days of gestation. Subsequently, intrauterine fetal death was confirmed at 14 weeks and 3 days of gestation. Regarding the third pregnancy, fetal ultrasonography at 11 weeks and 5 days of gestation showed mild fetal hydrops and moderate tricuspid valve regurgitation. At 16 weeks and 5 days of gestation, the fetus was suspected to have a left ventricular-type single ventricle, trace right ventricle, pulmonary atresia with intact ventricular septum, or cardiomyopathy. Cardiac function gradually declined at 26 weeks of gestation, and intrauterine fetal death was confirmed at 27 weeks and 5 days of gestation. The fourth pregnancy resulted in a normal heart with good progression and no abnormal baby. We submitted the first and second fetuses' umbilical cord, third fetus' placenta, and the fourth fetus' blood to genetic testing using whole exome analysis with next generation sequencing. Genetic analysis identified hemizygous PLD1 mutations in the first, second, and third fetuses. The fourth fetus was heterozygous. In addition, the parents were heterozygous for PLD1. This case is based on three consecutive cases of homozygosity for the PLD1 gene in the sibling cases and the fetuses with recurrent right ventricular valve dysplasia. This will elucidate the cause of recurrent congenital heart disease and intrauterine fetal death and may serve as an indicator for screening the next fetus. To date, homozygous mutations in PLD1 that repeat three times in a row are not reported, only up to two times. The novelty of this report is that it was repeated three times, followed by a heterozygous live birth.

CONCLUSIONS

This report is consistent with previous reports that mutations in PLD1 cause right ventricular valve dysplasia. However, there have been few case reports of PLD1 mutations, and we hope that this report will contribute to elucidate the causes of congenital heart disease, especially right ventricular valve dysplasia, and that the accumulation of such information will provide more detailed information on PLD1 mutations in heart disease.

Heterozygous loss-of-function DHX9 variants are associated with neurodevelopmental disorders: Human genetic and experimental evidences

DExH-box helicases are involved in unwinding of RNA and DNA. Among the 16 DExH-box genes, monoallelic variants of DHX16, DHX30, DHX34, and DHX37 are known to be associated with neurodevelopmental disorders. In particular, DHX30 is well established as a causative gene for neurodevelopmental disorders. Germline variants of DHX9, the closest homolog of DHX30, have not been reported until now as being associated with congenital disorders in humans, except that one de novo heterozygous variant, p.(Arg1052Gln) of the gene was identified during comprehensive screening in a patient with autism; unfortunately, the phenotypic details of this individual are unknown. Herein, we report a patient with a heterozygous de novo missense variant, p.(Gly414Arg) of DHX9 who presented with a short stature, intellectual disability, and ventricular non-compaction cardiomyopathy. The variant was located in the glycine codon of the ATP-binding site, G-C-G-K-T. To assess the pathogenicity of this variants, we generated transgenic Drosophila lines expressing human wild-type and mutant DHX9 proteins: 1) the mutant proteins showed aberrant localization both in the nucleus and the cytoplasm; 2) ectopic expression of wild-type protein in the visual system led to the rough eye phenotype, whereas expression of the mutant proteins had minimal effect; 3) overexpression of the wild-type protein in the retina led to a reduction in axonal numbers, whereas expression of the mutant proteins had a less pronounced effect. Furthermore, in a gene-editing experiment of Dhx9 G416 to R416, corresponding to p.(Gly414Arg) in humans, heterozygous mice showed a reduced body size, reduced emotionality, and cardiac conduction abnormality. In conclusion, we established that heterozygosity for a loss-of-function variant of DHX9 can lead to a new neurodevelopmental disorder.

A case of early-onset idiopathic chronic pancreatitis associated with a loss-of-function TRPV6 p.R483Q variant successfully treated by pancreatic duct stenting

Several pancreatitis-related genetic variants have been identified. Recently, the association of loss-of-function variants in the transient receptor potential cation channel subfamily V member 6 (TRPV6) gene and early-onset non-alcoholic chronic pancreatitis (CP) has been reported. However, detailed clinical presentation of the cases carrying TRPV6 variants remains largely unknown. We report a case of early CP carrying a TRPV6 variant in which recurrent attacks of pancreatitis were successfully managed by pancreatic duct stenting. A 12-year-old boy with CP was referred to our hospital for further investigation. He had experienced recurrent pancreatitis attacks since he was 11 years old. Pancreatic ductal anomalies were not identified on magnetic resonance cholangiopancreatography. Genetic analysis revealed that the patient had a loss-of-function TRPV6 c.1448G > A (p.R483Q) variant in a heterozygous form. Conservative treatments were not effective; thus, we placed pancreatic duct stent by endoscopic intervention, and the frequency of relapses have dramatically decreased. We present the first pediatric report of early CP associated with the TRPV6 variant that was successfully treated with pancreatic duct stenting. This case suggests that pancreatic duct stenting is effective in preventing the relapse of pancreatitis related to the TRPV6 variant.

Early laparoscopic cholecystectomy for acute cholecystitis following the Tokyo Guidelines 2018: a prospective single-center study of 201 consecutive cases

BACKGROUND

Early laparoscopic cholecystectomy (ELC) for acute cholecystitis (AC) poses multiple challenges. The Tokyo Guidelines 2018 (TG18) eliminated the time limit (< 72 h) and expanded the surgical indication to severe AC. This study aimed to evaluate the clinical outcomes of ELC for AC following the TG18 in a single high-volume center.

METHODS

From 2019 to 2021, we managed all AC patients with a TG18 flowchart and prospectively enrolled those who underwent ELC within 7 days of symptom onset. The primary outcome was overall morbidity, with a comparison between mild (Grade I) and moderate/severe (Grade II/III) AC.

RESULTS

During the study period, 201 patients underwent ELC was for Grade I (56.2%), II (40.3%), and III (3.5%) ACs. Mean age was 69 ± 15.2 years and time to surgery from symptom onset was 0 (12.9%), 1-3 (66.7%), and 4-7 days (20.4%). Mean operative time and blood loss were 118.9 ± 42.7 min and 57.8 ± 99.4 mL, respectively. The critical view of safety (CVS) was achieved in 76.1% of patients, and bailout procedures were performed in 21.4%. There were no open conversions or bile duct injuries. Major morbidities (Clavien-Dindo classification ≥ IIIa) were observed in 5.5% of cases and mortality in 0.5%. Comparing Grades II/III to Grade I, operative time was longer (112.3 vs. 127.3 min, p = 0.014), blood loss was higher (40.3 vs. 80.1 mL, p = 0.005), the CVS rate was lower (83.2 vs. 67.0%, p = 0.012), and the major morbidity rate was higher (1.8 vs. 10.2%, p = 0.012). In the subgroup analysis of Grade II/III, there were no significant differences in major morbidities (p = 0.288) between the two groups (0-3 vs. 4-7 days).

CONCLUSION

ELC for AC following TG18 is feasible with low morbidity rates. However, ELC for Grade II/III ACs remains challenging, and surgeons must carefully assess intraoperative difficulties and surgical risks before proceeding.

Molecular diagnosis of 405 individuals with autism spectrum disorder

Autism spectrum disorder (ASD) is caused by combined genetic and environmental factors. Genetic heritability in ASD is estimated as 60-90%, and genetic investigations have revealed many monogenic factors. We analyzed 405 patients with ASD using family-based exome sequencing to detect disease-causing single-nucleotide variants (SNVs), small insertions and deletions (indels), and copy number variations (CNVs) for molecular diagnoses. All candidate variants were validated by Sanger sequencing or quantitative polymerase chain reaction and were evaluated using the American College of Medical Genetics and Genomics/Association for Molecular Pathology guidelines for molecular diagnosis. We identified 55 disease-causing SNVs/indels in 53 affected individuals and 13 disease-causing CNVs in 13 affected individuals, achieving a molecular diagnosis in 66 of 405 affected individuals (16.3%). Among the 55 disease-causing SNVs/indels, 51 occurred de novo, 2 were compound heterozygous (in one patient), and 2 were X-linked hemizygous variants inherited from unaffected mothers. The molecular diagnosis rate in females was significantly higher than that in males. We analyzed affected sibling cases of 24 quads and 2 quintets, but only one pair of siblings shared an identical pathogenic variant. Notably, there was a higher molecular diagnostic rate in simplex cases than in multiplex families. Our simulation indicated that the diagnostic yield is increasing by 0.63% (range 0-2.5%) per year. Based on our simple simulation, diagnostic yield is improving over time. Thus, periodical reevaluation of ES data should be strongly encouraged in undiagnosed ASD patients.

Newborn screening for spinal muscular atrophy in Osaka -challenges in a Japanese pilot study

OBJECTIVE

This study aimed to establish an optional newborn screening program for spinal muscular atrophy (SMA-NBS) in Osaka.

METHODS

A multiplex TaqMan real-time quantitative polymerase chain reaction assay was used to screen for SMA. Dried blood spot samples obtained for the optional NBS program for severe combined immunodeficiency, which covers about 50% of the newborns in Osaka, were used. To obtain informed consent, participating obstetricians provided information about the optional NBS program to all parents by giving leaflets to prospective parents and uploading the information onto the internet. We prepared a workflow so that babies that were diagnosed with SMA through the NBS could be treated immediately.

RESULTS

From 1 February 2021 to 30 September 2021, 22,951 newborns were screened for SMA. All of them tested negative for survival motor neuron (SMN)1 deletion, and there were no false-positives. Based on these results, an SMA-NBS program was established in Osaka and included in the optional NBS programs run in Osaka from 1 October 2021. A positive baby was found by screening, diagnosed with SMA (the baby possessed 3 copies of the SMN2 gene and was pre-symptomatic), and treated immediately.

CONCLUSION

The workflow of the Osaka SMA-NBS program was confirmed to be useful for babies with SMA.

Association between cerebrospinal fluid parameters and developmental and neurological status in glucose transporter 1 deficiency syndrome

OBJECTIVE

In glucose transporter 1 deficiency syndrome (Glut1DS), cerebrospinal fluid glucose (CSFG) and CSFG to blood glucose ratio (CBGR) show significant differences among groups classified by phenotype or genotype. The purpose of this study was to investigate the association between these biochemical parameters and Glut1DS severity.

METHODS

The medical records of 45 patients who visited Osaka University Hospital between March 2004 and December 2021 were retrospectively examined. Neurological status was determined using the developmental quotient (DQ), assessed using the Kyoto Scale of Psychological Development 2001, and the Scale for the Assessment and Rating of Ataxia (SARA). CSF parameters included CSFG, CBGR, and CSF lactate (CSFL).

RESULTS

CSF was collected from 41 patients, and DQ and SARA were assessed in 24 and 27 patients, respectively. Simple regression analysis showed moderate associations between neurological status and biochemical parameters. CSFG resulted in a higher R² than CBGR in these analyses. CSF parameters acquired during the first year of life were not comparable to those acquired later. CSFL was measured in 16 patients (DQ and SARA in 11 and 14 patients, respectively). Although simple regression analysis also showed moderate associations between neurological status and CSFG and CSFL, the multiple regression analysis for DQ and SARA resulted in strong associations through the use of a combination of CSFG and CSFL as explanatory variables.

CONCLUSION

The severity of Glut1DS can be predicted from CSF parameters. Glucose and lactate are independent contributors to the developmental and neurological status in Glut1DS.

Time course of serum neuron-specific enolase levels from infancy to early adulthood in a female patient with beta-propeller protein-associated neurodegeneration

Beta-propeller protein-associated neurodegeneration (BPAN), a subgroup of neurodegeneration with brain iron accumulation, is typically characterized by non-progressive global developmental delay and seizures in childhood, followed by progressive neurological decline with parkinsonism and dementia in adolescence or early adulthood. It is difficult to clinically identify a patient with BPAN in childhood. Recent studies reported that serum levels of neuron-specific enolase (NSE) were elevated in children with BPAN. We reviewed the time course of serum NSE levels in a 21-year-old female patient genetically diagnosed (a de novo WDR45 variant c.268A > T) with BPAN, which was suspected based on prolonged elevation of serum NSE. There was an overall tendency for serum NSE levels to decrease in a stepwise fashion. The peak serum NSE level was observed during the first 2 years of age and then decreased rapidly in 1 year. High serum NSE levels persisted between 3 and 11 years of age. Subsequently, serum NSE levels decreased and plateaued after 13 years of age. There were tendencies for both blood AST and LDH levels to decrease over time in parallel with serum NSE levels. Serum NSE levels may be a diagnostic biomarker of BPAN in children but becomes of less value in identifying a patient with BPAN after childhood.

Interstitial microdeletions of 3q26.2q26.31 in two patients with neurodevelopmental delay and distinctive features

Interstitial microdeletions in the long arm of chromosome 3 are rare. In this study, we identified two patients with approximately 5-Mb overlapping deletions in the 3q26.2q26.31 region. Both patients showed neurodevelopmental delays, congenital heart defects, and distinctive facial features. One of them showed growth deficiency and brain abnormalities, as shown on a magnetic resonance imaging scan. Haploinsufficiency of NLGN1 and FNDC3B present in the common deletion region was considered to be responsible for neurodevelopmental delay and the distinctive features, respectively. The possibility of unmasked variants in PLD1 was considered and analyzed, but no possible pathogenic variant was found, and the mechanism of the congenital heart defects observed in the patients is unknown. Because 3q26.2q26.31 deletions are rare, more information is required to establish genotype-phenotype correlations associated with microdeletions in this region.

Diagnosis of Prader-Willi syndrome and Angelman syndrome by targeted nanopore long-read sequencing

The CpG island flanking the promoter region of SNRPN on chromosome 15q11.2 contains CpG sites that are completely methylated in the maternally derived allele and unmethylated in the paternally derived allele. Both unmethylated and methylated alleles are observed in normal individuals. Only the methylated allele is observed in patients with Prader-Willi syndrome, whereas only the unmethylated allele is observed in those with Angelman syndrome. Hence, detection of aberrant methylation at the differentially methylated region is fundamental to the molecular diagnosis of Prader-Willi syndrome and Angelman syndromes. Traditionally, bisulfite treatment and methylation-sensitive restriction enzyme treatment or methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) have been used. We here developed a long-read sequencing assay that can distinguish methylated and unmethylated CpG sites at 15q11.2 by the difference in current intensity generated from nanopore reads. We successfully diagnosed 4 Prader-Willi syndrome patients and 3 Angelman syndrome patients by targeting differentially methylated regions. Concurrent copy number analysis, homozygosity analysis, and structural variant analysis also allowed us to precisely delineate the underlying pathogenic mechanisms, including gross deletion, uniparental heterodisomy, uniparental isodisomy, or imprinting defect. Furthermore, we showed allele-specific methylation in imprinting-related differentially methylated regions on chromosomes 6, 7, 11, 14, and 20 in a normal individual together with 4 Prader-Willi patients and 3 Angelman syndrome patients. Hence, presently reported method is likely to be applicable to the diagnosis of imprinting disorders other than Prader-Willi syndrome and Angelman syndrome as well.

Case Report: Molecular autopsy underlie COVID-19-associated sudden, unexplained child mortality

Herein, we report a child with COVID-19 and seemingly no underlying disease, who died suddenly. The autopsy revealed severe anemia and thrombocytopenia, splenomegaly, hypercytokinemia, and a rare ectopic congenital coronary origin. Immunohistochemical analysis demonstrated that the patient had acute lymphoblastic leukemia of the B-cell precursor phenotype (BCP-ALL). The complex cardiac and hematological abnormalities suggested the presence of an underlying disease; therefore, we performed whole-exome sequencing (WES). WES revealed a leucine-zipper-like transcription regulator 1 (LZTR1) variant, indicating Noonan syndrome (NS). Therefore, we concluded that the patient had underlying NS along with coronary artery malformation and that COVID-19 infection may have triggered the sudden cardiac death due to increased cardiac load caused by high fever and dehydration. In addition, multiple organ failure due to hypercytokinemia probably contributed to the patient's death. This case would be of interest to pathologists and pediatricians because of the limited number of NS patients with LZTR1 variants; the complex combination of an LZTR1 variant, BCP-ALL, and COVID-19; and a rare pattern of the anomalous origin of the coronary artery. Thus, we highlight the significance of molecular autopsy and the application of WES with conventional diagnostic methods.

A Case of Mesangial Proliferative Nephritis Caused by Slow Cryoglobulin

The patient was a woman in her 60s. She was found to have proteinuria on a health checkup. She did not have any particular subjective symptoms, and no definitive diagnosis was made, despite serological findings indicative of immune abnormalities. A renal biopsy was performed. Light microscopy of renal tissue section revealed mesangial proliferative nephritis. Electron microscopic findings included electron-dense deposits and fibrillar/tubular structures with a diameter of 20-30 nm. These findings suggested the presence of cryoglobulin (CG), but CG was not detected in qualitative or quantitative hematologic tests. Thus, the serum samples were stored at 37°C for a long period of time and then cooled to 4°C. When the obtained precipitates were examined, CG was successfully detected. CG that precipitates only after a long period of time is referred to as slow cryoglobulin (sCG), and sCG is extremely rare. The present case is the first documented case, to our knowledge, of renal disorders caused by sCG. It should be noted that there are some cases in which it takes much time for CG to precipitate. Thus, when CG cannot be detected, it is necessary to spend much time to determine whether CG precipitates.

Long-read sequence analysis for clustered genomic copy number aberrations revealed architectures of intricately intertwined rearrangements

Most chromosomal aberrations revealed by chromosomal microarray testing (CMA) are simple; however, very complex chromosomal structural rearrangements can also be found. Although the mechanism of structural rearrangements has been gradually revealed, not all mechanisms have been elucidated. We analyzed the breakpoint-junctions (BJs) of two or more clustered copy number variations (CNVs) in the same chromosome arms to understand their conformation and the mechanism of complex structural rearrangements. Combining CMA with long-read whole-genome sequencing (WGS) analysis, we successfully determined all BJs for the clustered CNVs identified in four patients. Multiple CNVs were intricately intertwined with each other, and clustered CNVs in four patients were involved in global complex chromosomal rearrangements. The BJs of two clustered deletions identified in two patients showed microhomologies, and their characteristics were explained by chromothripsis. In contrast, the BJs in the other two patients, who showed clustered deletions and duplications, consisted of blunt-end and nontemplated insertions. These findings could be explained only by alternative nonhomologous end-joining, a mechanism related to polymerase theta. All the patients had at least one inverted segment. Three patients showed cryptic aberrations involving a disruption and a deletion/duplication, which were not detected by CMA but were first identified by WGS. This result suggested that complex rearrangements should be considered if clustered CNVs are observed in the same chromosome arms. Because CMA has potential limitations in genotype-phenotype correlation analysis, a more detailed analysis by whole genome examination is recommended in cases of suspected complex structural aberrations.

Three KINSSHIP syndrome patients with mosaic and germline AFF3 variants

AFF3 at 2q11.2 encodes the nuclear transcriptional activator AF4/FMR2 Family Member 3. AFF3 constitutes super elongation complex like 3, which plays a role in promoting the expression of genes involved in neurogenesis and development. The degron motif in AFF3 with nine highly conserved amino acids is recognized by E3 ubiquitin ligase to induce protein degradation. Recently, AFF3 missense variants in this region and variants featuring deletion including this region were identified and shown to cause KINSSHIP syndrome. In this study, we identified two novel and one previously reported missense variants in the degron of AFF3 in three unrelated Japanese patients. Notably, two of these three variants exhibited mosaicism in the examined tissues. This study suggests that mosaic variants also cause KINSSHIP syndrome, showing various phenotypes.

A novel homozygous CHMP1A variant arising from segmental uniparental disomy causes pontocerebellar hypoplasia type 8

Pontocerebellar hypoplasia (PCH) is currently classified into 16 subgroups. Using mostly next-generation sequencing, pathogenic variants have been identified in as many as 24 PCH-associated genes. PCH type 8 (PCH8) is a rare heterogeneous disorder. Its clinical presentation includes severe development delay, increased muscle tone, microcephaly, and magnetic resonance imaging (MRI) abnormalities such as reduced cerebral white matter, a thin corpus callosum, and brainstem and cerebellar hypoplasia. To date, only two variants in the CHMP1A gene (MIM: 164010), NM_002768.5: c.88 C > T (p.Glu30*) and c.28-13 G > A, have been identified homozygously in seven patients with PCH8 from four families (MIM: 614961). CHMP1A is a subunit of the endosomal sorting complex required for transport III (ESCRT-III), which regulates the formation and release of extracellular vesicles. Biallelic CHMP1A loss of function impairs the ESCRT-III-mediated release of extracellular vesicles, which causes impaired progenitor proliferation in the developing brain. Herein, we report a patient with PCH8 who had a homozygous CHMP1A variant, c.122delA (p.Asn41Metfs*2), which arose from segmental uniparental disomy. Although our patient had similar MRI findings to those of previously reported patients, with no progression, we report some novel neurological and developmental findings that expand our knowledge of the clinical consequences associated with CHMP1A variants.

Genetic and clinical landscape of childhood cerebellar hypoplasia and atrophy

PURPOSE

Cerebellar hypoplasia and atrophy (CBHA) in children is an extremely heterogeneous group of disorders, but few comprehensive genetic studies have been reported. Comprehensive genetic analysis of CBHA patients may help differentiating atrophy and hypoplasia and potentially improve their prognostic aspects.

METHODS

Patients with CBHA in 176 families were genetically examined using exome sequencing. Patients with disease-causing variants were clinically evaluated.

RESULTS

Disease-causing variants were identified in 96 of the 176 families (54.5%). After excluding 6 families, 48 patients from 42 families were categorized as having syndromic associations with CBHA, whereas the remaining 51 patients from 48 families had isolated CBHA. In 51 patients, 26 aberrant genes were identified, of which, 20 (76.9%) caused disease in 1 family each. The most prevalent genes were CACNA1A, ITPR1, and KIF1A. Of the 26 aberrant genes, 21 and 1 were functionally annotated to atrophy and hypoplasia, respectively. CBHA+S was more clinically severe than CBHA-S. Notably, ARG1 and FOLR1 variants were identified in 2 families, leading to medical treatments.

CONCLUSION

A wide genetic and clinical diversity of CBHA was revealed through exome sequencing in this cohort, which highlights the importance of comprehensive genetic analyses. Furthermore, molecular-based treatment was available for 2 families.

Clinical and molecular findings in three Japanese patients with N-acetylneuraminic acid synthetase-congenital disorder of glycosylation (NANS-CDG)

We report clinical and molecular findings in three Japanese patients with N-acetylneuraminic acid synthetase-congenital disorder of glycosylation (NANS-CDG). Patient 1 exhibited a unique constellation of clinical features including marked hydrocephalus, spondyloepimetaphyseal dysplasia (SEMD), and thrombocytopenia which is comparable to that of an infant reported by Faye-Peterson et al., whereas patients 2 and 3 showed Camera-Genevieve type SMED with intellectual/developmental disability which is currently known as the sole disease name for NANS-CDG. Molecular studies revealed a maternally inherited likely pathogenic c.207del:p.(Arg69Serfs*57) variant and a paternally derived likely pathogenic c.979_981dup:p.(Ile327dup) variant in patient 1, a homozygous likely pathogenic c.979_981dup:p.(Ile327dup) variant caused by maternal segmental isodisomy involving NANS in patient 2, and a paternally inherited pathogenic c.133-12T>A variant leading to aberrant splicing and a maternally inherited likely pathogenic c.607T>C:p.(Tyr203His) variant in patient 3 (reference mRNA: NM_018946.4). The results, together with previously reported data, imply that (1) NANS plays an important role in postnatal growth and fetal brain development; (2) SMED is recognizable at birth and shows remarkable postnatal evolution; (3) NANS-CDG is associated with low-normal serum sialic acid, obviously elevated urine N-acetylmannosamine, and normal N- and O-glycosylation of serum proteins; and (4) NANS-CDG is divided into Camera-Genevieve type and more severe Faye-Peterson type.

Interstitial deletions in the proximal regions of 6q: 12 original cases and a literature review

Interstitial microdeletions in the proximal region of the long arm of chromosome 6 are rare. Herein we have reported 12 patients with developmental delays associated with interstitial microdeletions in 6q ranging from q12 to q22. The microdeletions were detected by chromosomal microarray testing. To confirm the clinical significance of these deletions, genotype-phenotype correlation analysis was performed using genetic and predicted loss-of-function data. SIM1 was recognized as the gene responsible for developmental delay, particularly in Prader-Willi syndrome-like phenotypes. Other genes possibly related to developmental delay were ZNF292, PHIP, KCNQ5, and NUS1. To further establish the correlation between the genotype and phenotype, more patient information is required.

LB0002 BARICITINIB IN JUVENILE IDIOPATHIC ARTHRITIS: A PHASE 3, DOUBLE-BLIND, PLACEBO-CONTROLLED, WITHDRAWAL, EFFICACY AND SAFETY STUDY

Background

Baricitinib is a JAK1/2 selective inhibitor approved for the treatment of rheumatoid arthritis. Juvenile idiopathic arthritis (JIA) is a group of diseases characterized by immune mediated chronic arthritis which often requires treatment with conventional synthetic or biologic disease-modifying antirheumatic drugs (cs or b-DMARDs).

Objectives

To investigate baricitinib efficacy and safety in pediatric patients with JIA and an inadequate response to cs or b-DMARDs.

Methods

This Phase 3 multicenter, double-blind, withdrawal, efficacy, and safety study, enrolled patients (pts) age 2 to <18 years with extended oligo- or poly-articular JIA, ERA, or JPsA, per ILAR criteria, and an inadequate response to ≥1 cs and/or b-DMARDs (NCT03773978). There were 3 periods: a 2-week (wk) pharmacokinetic/safety assessment (PKS), a 12-wk open-label lead-in (OLLI), and an up-to 32-wk double-blind withdrawal (DBW). Dosage and safety were confirmed in the PKS and then pts, including those from the PKS, enrolled in the OLLI, receiving age-based, oral, once daily doses of baricitinib. Pts with a JIA-ACR30 response at wk12, end of OLLI, entered the DBW to be randomized 1:1 to continued baricitinib or newly started placebo (PBO) and remained until flare or up to wk32. Primary endpoint was time to flare during the DBW. Secondary endpoints included JIA-ACR30/50/70/90 response rates at wk12, and proportion of pts with a flare during the DBW. Survival curves were estimated using the Kaplan-Meier method.

Results

Of 220 pts enrolled, 29 participated in the PKS, 219 entered the OLLI, and 163 entered the DBW. The JIA-ACR30/50/70/90 response at wk12 was 76.3%/63.5%/46.1%/20.1%, respectively. During the DBW, time of flare was significantly shorter with PBO vs baricitinib (hazard ratio 0.24 [95% CI 0.13,0.45], p<0.001; Figure 1). The proportion of pts with a flare during the DBW was significantly lower for baricitinib vs PBO (14 (17.1%) vs. 41 (50.6%), p<0.001). In the PKS and OLLI periods, 126 (57.3%) pts reported ≥1 treatment emergent adverse event (TEAE), while 6 (2.7%) reported ≥1 serious adverse event (SAE); Table 1. In the DBW, 38 (46.9%) and 54 (65.9%) pts reported ≥1 TEAE for PBO and baricitinib, respectively, whereas those with ≥1 SAE were 3 (3.7%) and 4 (4.9%). The mean wks of exposure was higher in the baricitinib vs PBO group during DBW (26.34 vs 18.91) due to study design. There were no deaths, cardiovascular events or uveitis and 1 case of herpes zoster. Table 1.

Conclusion

Baricitinib significantly reduced time to and frequency of JIA flares in pts with JIA versus PBO, and improved JIA-ACR scores in the majority of pts within 12wks. Safety findings were consistent with the known safety profile in adult rheumatoid arthritis indications. These findings support baricitinib as a treatment for signs and symptoms of JIA with an inadequate response to cs or b-DMARDs.

References

[1]Giannini EH, et. al. Preliminary definition of improvement in juvenile arthritis. Arthritis Rheum 1997; 40: 1202-1209.

[2]Brunner HI, et. al. Preliminary definition of disease flare in juvenile rheumatoid arthritis. J Rheumatol 2002; 29(5):1058-64.

Disclosure of Interests

Athimalaipet Ramanan Consultant of: Eli Lilly and Company, Abbvie, Roche, UCB, Novartis, Pfizer, and Sobi, Grant/research support from: Eli Lilly and Company, Pierre Quartier Consultant of: Eli Lilly and Company, Abbvie, Amgen, BMS, Novartis, Novimmune, Pfizer, Swedish Orphan Biovitrum, SANOFI, Speakers bureau: Abbvie, Novartis, Pfizer, Swedish Orphan Biovitrum, Nami Okamoto Consultant of: Swedish Orphan Biovitrum, Eli Lilly and Company, Speakers bureau: AbbVie, Eli Lilly and Company, Sanofi, Asahi Kasei Medical, Mitsubishi Tanabe Pharma, Bristol Myers Squibb, Pfizer Japan, Ayumi Pharma, Eisai, Torii Pharma, GlaxoSmithKline, Kyorin Pharma, Novartis, Chugai Pharmaceutical, Teijin Pharma, Gabriella Meszaros Employee of: Eli Lilly and Company, Joana Araujo Employee of: Eli Lilly and Company, Zhongkai Wang Employee of: Eli Lilly and Company, Ran Liao Employee of: Eli Lilly and Company, Brenda Crowe Employee of: Eli Lilly and Company, Xin Zhang Employee of: Eli Lilly and Company, Rodney Decker Employee of: Eli Lilly and Company, Stuart Keller Employee of: Eli Lilly and Company, Hermine Brunner Consultant of: AbbVie, Astra Zeneca-Medimmune, Biogen, Boehringer, Bristol-Myers Squibb, Celgene, Eli Lilly, EMD Serono, Idorsia, Cerocor, Janssen, GlaxoSmithKline, F. Hoffmann-La Roche, Merck, Novartis, R-Pharm, Sanofi, Speakers bureau: Novartis, Pfizer, GlaxoSmithKline, Nicolino Ruperto Consultant of: Eli Lilly and Company, Ablynx, Amgen, Astrazeneca-Medimmune, Aurinia, Bayer, Bristol Myers and Squibb, Cambridge Healthcare Research (CHR), Celgene, Domain therapeutic, Eli-Lilly, EMD Serono, Glaxo Smith and Kline, Idorsia, Janssen, Novartis, Pfizer, Sobi, UCB, Speakers bureau: Eli Lilly and Company, Glaxo Smith and Kline, Pfizer, Sobi, UCB

Genome Analysis in Sick Neonates and Infants: High-yield Phenotypes and Contribution of Small Copy Number Variations

OBJECTIVE

To delineate the diagnostic efficacy of medical exome, whole exome, and whole genome sequencing according to primary symptoms, the contribution of small copy number variations, and the impact of molecular diagnosis on clinical management.

STUDY DESIGN

This was a prospective study of 17 tertiary care centers in Japan, conducted between April 2019 and March 2021. Critically ill neonates and infants less than 6 months of age were recruited in neonatal intensive care units and in outpatient clinics. The patients underwent medical exome, whole exome, or whole genome sequencing as the first tier of testing. Patients with negative results after medical exome or whole exome sequencing subsequently underwent whole genome sequencing. The impact of molecular diagnosis on clinical management was evaluated through contacting primary care physicians.

RESULTS

Of the 85 patients, 41 (48%) had positive results. Based on the primary symptoms, patients with metabolic phenotypes had the highest diagnostic yield (67%, 4/6 patients), followed by renal (60%, 3/5 patients), and neurologic phenotypes (58%, 14/24 patients). Among them, 4 patients had pathogenic small copy number variations identified using whole genome sequencing. In the 41 patients with a molecular diagnosis, 20 (49%) had changes in clinical management.

CONCLUSIONS

Genome analysis for critically ill neonates and infants had a high diagnostic yield for metabolic, renal, and neurologic phenotypes. Small copy number variations detected using whole genome sequencing contributed to the overall molecular diagnosis in 5% of all the patients. The resulting molecular diagnoses had a significant impact on clinical management.

Utility of Concurrent Surgical Treatment Strategy with Thoracoscopic Esophagectomy for Patients with Synchronous Esophageal and Head and Neck Cancer

Background: Patients with esophageal squamous cell cancer (ESCC) have a high frequency to coincide with head and neck cancer (HNC). This study aims to analyze the treatment results and prognosis of patients with synchronous ESCC and HNC. Methods: From January 2016 to December 2019, 5 patients underwent concurrent surgical resection of synchronous ESCC and HNC in our institution. We retrospectively reviewed the surgical outcomes and prognosis of these patients with synchronous ESCC and HNC (HNEC group) and compared the results with those of 20 patients who underwent esophagectomy with three regional lymph node dissections for ESCC during the same period (EC group). Results: The locations of HNCs were pharynx/tongue (4/1) and the clinical stages were Stage IV in all patients. Meanwhile, the clinical stages of ESCCs were Stages 0/I/II/III (1/1/2/1). All patients underwent thoracoscopic esophagectomy. The surgical procedures concurrently performed for HNC were pharyngolaryngectomy with free jejunum transfer in 3 patients, wide tongue and mandibular segment resection with mandibular reconstruction in 1 patient, and mandibular transection with radial forearm flap reconstruction in 1 patient. There was no significant difference in the frequency of postoperative complication between these two groups. The HNEC group had a significantly shorter recurrence-free survival than the EC group (P = .046). Conclusion: Head and neck surgery with thoracoscopic esophagectomy can be safely performed concurrently with local control. The risk of recurrence is higher in ESCC patients with HNC; therefore, it is important to move on to adjuvant therapy without delay.

[A Case of Delayed Anastomotic Leakage after Ileocecal Resection in a Hemodialysis Patient]

A 66-year-old man was referred to our department with the diagnosis of ascending colon cancer. He was undergoing dialysis for chronic renal failure due to diabetic nephropathy. Laparoscopic ileocecal resection was planned for the ascending colon cancer, but the procedure was converted to laparotomy owing to intraoperative bleeding. The patient was discharged from the hospital after 7 days. On the 14th postoperative day, the patient presented with purulent drainage from the wound and fever and was diagnosed to have a minor anastomotic leak. The suture of the anterior sheath was exposed in part of the wound. The patient's general condition was stable, and conservative treatment was planned. However, when he coughed, the wound separated and the intestine prolapsed, and emergency surgery was performed. Intraoperative findings showed leakage of intestinal fluid from the anastomotic border, and we diagnosed delayed suture failure. We present a rare case of delayed anastomotic leakage in a hemodialysis patient.

Laparoscopic low anterior resection for rectal cancer associated with Leriche syndrome: a case report

A 78-year-old male presented with a positive fecal occult blood test. Rectal cancer was detected during lower gastrointestinal endoscopy, and further investigations led to a diagnosis of cT1N0M0 cStage I (UICC classification, 8th edition). Preoperative contrast-enhanced computed tomography (CT) showed that the patient also had Leriche syndrome, which is associated with reduced blood flow to the rectum that may result in ischemic anastomosis during rectal cancer surgery with anastomotic reconstruction. The inferior epigastric arteries often function as collateral pathways to the lower limbs in patients with Leriche syndrome; therefore, care is needed to avoid vascular damage during trocar insertion when performing laparoscopic surgeries. We herein described a case of safe laparoscopic low anterior resection in a rectal cancer patient with Leriche syndrome using vascular architecture images obtained by preoperative CT angiography.

Large-scale discovery of novel neurodevelopmental disorder-related genes through a unified analysis of single-nucleotide and copy number variants

Background

Previous large-scale studies of de novo variants identified a number of genes associated with neurodevelopmental disorders (NDDs); however, it was also predicted that many NDD-associated genes await discovery. Such genes can be discovered by integrating copy number variants (CNVs), which have not been fully considered in previous studies, and increasing the sample size.

Methods

We first constructed a model estimating the rates of de novo CNVs per gene from several factors such as gene length and number of exons. Second, we compiled a comprehensive list of de novo single-nucleotide variants (SNVs) in 41,165 individuals and de novo CNVs in 3675 individuals with NDDs by aggregating our own and publicly available datasets, including denovo-db and the Deciphering Developmental Disorders study data. Third, summing up the de novo CNV rates that we estimated and SNV rates previously established, gene-based enrichment of de novo deleterious SNVs and CNVs were assessed in the 41,165 cases. Significantly enriched genes were further prioritized according to their similarity to known NDD genes using a deep learning model that considers functional characteristics (e.g., gene ontology and expression patterns).

Results

We identified a total of 380 genes achieving statistical significance (5% false discovery rate), including 31 genes affected by de novo CNVs. Of the 380 genes, 52 have not previously been reported as NDD genes, and the data of de novo CNVs contributed to the significance of three genes (GLTSCR1, MARK2, and UBR3). Among the 52 genes, we reasonably excluded 18 genes [a number almost identical to the theoretically expected false positives (i.e., 380 × 0.05 = 19)] given their constraints against deleterious variants and extracted 34 “plausible” candidate genes. Their validity as NDD genes was consistently supported by their similarity in function and gene expression patterns to known NDD genes. Quantifying the overall similarity using deep learning, we identified 11 high-confidence (> 90% true-positive probabilities) candidate genes: HDAC2, SUPT16H, HECTD4, CHD5, XPO1, GSK3B, NLGN2, ADGRB1, CTR9, BRD3, and MARK2.

Conclusions

We identified dozens of new candidates for NDD genes. Both the methods and the resources developed here will contribute to the further identification of novel NDD-associated genes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-022-01042-w.

Six-month survival of a monochorionic monoamniotic twin with sirenomelia

BACKGROUND

Sirenomelia is a congenital malformation of the lower body characterized by a single midline lower limb and severe urogenital and gastrointestinal malformations. Sirenomelia is rare (estimated incidence of approximately 1/100,000) and usually lethal in the perinatal period.

CASE

A 2,042 g Japanese male infant, one of monochorionic monoamniotic twins, was born at 34 weeks of gestation by elective caesarean section. Sirenomelia was prenatally diagnosed. Single midline lower limb, bilateral dysplastic kidneys, an omphalomesenteric fistula, colon atresia, imperforate anus, indiscernible genital structures, and myelomeningocele were detected at birth. The amniotic fluid volume was normal throughout the pregnancy course, which led to appropriate lung maturation of the twin with sirenomelia. Although renal replacement therapy was initiated soon after birth, stable peritoneal dialysis was difficult because of the limited intraperitoneal space, and the infant frequently developed peritonitis. He died of sudden cardiorespiratory arrest at 6 months of age. Postmortem examination showed bilateral dysplastic kidneys, agenesis of the ureters and urinary bladder, abnormal branching and agenesis of the distal colon, bilateral inguinal hernias, and small testes.

CONCLUSION

Infants with sirenomelia, even those with end-stage kidney disease at birth, may survive if they have a stable cardiorespiratory status at birth and renal replacement therapy is appropriately initiated.

Phenotypic and mutational spectrum of ROR2-related Robinow syndrome

Robinow syndrome is characterized by a triad of craniofacial dysmorphisms, disproportionate-limb short stature and genital hypoplasia. A significant degree of phenotypic variability seems to correlate with different genes/loci. Disturbances of the non-canonical WNT-pathway have been identified as the main cause of the syndrome. Biallelic variants in ROR2 cause an autosomal recessive form of the syndrome with distinctive skeletal findings. Twenty-two patients with a clinical diagnosis of autosomal recessive Robinow syndrome were screened for variants in ROR2 using multiple molecular approaches. We identified 25 putatively pathogenic ROR2 variants, 16 novel, including single nucleotide variants and exonic deletions. Detailed phenotypic analyses revealed that all subjects presented with a prominent forehead, hypertelorism, short nose, abnormality of the nasal tip, brachydactyly, mesomelic limb shortening, short stature and genital hypoplasia in male patients. A total of 19 clinical features were present in more than 75% of the subjects, thus pointing to an overall uniformity of the phenotype. Disease-causing variants in ROR2, contribute to a clinically recognizable AR trait phenotype with multiple skeletal defects. A comprehensive quantitative clinical evaluation this cohort delineated the phenotypic spectrum of ROR2-related Robinow syndrome. The identification of exonic deletion variant alleles further supports the contention of a loss-of-function mechanism in the etiology of the syndrome. This article is protected by copyright. All rights reserved.

Maternal Uniparental Isodisomy of Chromosome 4 and 8 in Patients with Retinal Dystrophy: SRD5A3-Congenital Disorders of Glycosylation and RP1-Related Retinitis Pigmentosa

Purpose: Uniparental disomy (UPD) is a rare chromosomal abnormality. We performed whole-exosome sequencing (WES) in cases of early-onset retinal dystrophy and identified two cases likely caused by UPD. Herein, we report these two cases and attempt to clarify the clinical picture of retinal dystrophies caused by UPD. Methods: WES analysis was performed for two patients and their parents, who were not consanguineous. Functional analysis was performed in cases suspected of congenital disorders of glycosylation (CDG). We obtained clinical case data and reviewed the literature. Results: In case 1, a novel c.57G>C, p.(Trp19Cys) variant in SRD5A3 was detected homozygously. Genetic analysis suggested a maternal UPD on chromosome 4, and functional analysis confirmed CDG. Clinical findings showed early-onset retinal dystrophy, intellectual disability, and epilepsy. In case 2, an Alu insertion (c.4052_4053ins328, p.[Tyr1352Alafs]) in RP1 was detected homozygously. Maternal UPD on chromosome 8 was suspected. The clinical picture was consistent with RP1-related retinitis pigmentosa. Although the clinical features of retinal dystrophy by UPD may vary, most cases present with childhood onset. Conclusions: There have been limited reports of retinal dystrophy caused by UPD, suggesting that it is rare. Genetic counseling may be encouraged in pediatric cases of retinal dystrophy.

Comprehensive genetic analysis using next-generation sequencing for the diagnosis of nephronophthisis-related ciliopathies in the Japanese population

Nephronophthisis is an autosomal-recessive kidney disease that is caused by abnormalities in primary cilia. Nephronophthisis-related ciliopathies (NPHP-RCs) are a common cause of end-stage kidney disease (ESKD) in children and adolescents. NPHP-RCs are often accompanied by extrarenal manifestations, including intellectual disability, retinitis pigmentosa, or polydactyly. Although more than 100 causative genes have been identified, its diagnosis is difficult because the clinical features of each mutation often overlap. From September 2010 to August 2021, we performed genetic analysis, including next-generation sequencing (NGS), in 574 probands with kidney dysfunction and retrospectively studied cases genetically diagnosed with NPHP-RCs. RESULTS: We detected mutations related to NPHP-RCs in 93 patients from 83 families. Members of 60 families were diagnosed using NGS, and the mutations and the corresponding number of families are as follows: NPHP1 (24), NPHP3 (10), OFD1 (7), WDR35 (5), SDCCAG8 (4), BBS10 (3), TMEM67 (3), WDR19 (3), BBS1 (2), BBS2 (2), IFT122 (2), IFT140 (2), IQCB1 (2), MKKS (2), SCLT1 (2), TTC21B (2), ALMS1 (1), ANKS6 (1), BBS4 (1), BBS12 (1), CC2D2A (1), DYNC2H1 (1), IFT172 (1), and MAPKBP1 (1). A total of 39 cases (41.9%) progressed to ESKD at the time of genetic analysis, whereas 58 cases (62.3%) showed extrarenal manifestations, the most common being developmental delay, intellectual disability, and autism spectrum disorder in 44 patients. Comprehensive genetic analysis using NGS is useful for diagnosing patients with NPHP-RCs.

Mass Spectrometry of Transferrin and Apolipoprotein CIII from Dried Blood Spots for Congenital Disorders of Glycosylation

Dried blood spot (DBS) is the standard specimen for the newborn screening of inborn errors of metabolism (IEM) by tandem mass spectrometry. Availability of DBS for the mass spectrometric analysis of the diagnostic marker proteins, transferrin (Tf) and apolipoprotein CIII (apoCIII), of congenital disorders of glycosylation (CDG) was examined. Recovery of Tf from DBS was only slightly reduced compared with fresh serum. Although oxidation of the core polypeptides was observed, glycans of Tf and apoCIII were unaffected by storage of DBS in the ambient environment for at least 1 month. The combination of DBS and the triple quadrupole mass spectrometer used for IEM screening was sufficient to characterize the aberrant glycoprofiles of Tf and apoCIII in CDG. DBS or dried serum spot on filter paper can reduce the cost of sample transportation and potentially promote mass spectrometric screening of CDG.

Electrospray Ionization Mass Spectrometry of Transferrin: Use of Quadrupole Mass Analyzers for Congenital Disorders of Glycosylation

Electrospray ionization (ESI) mass spectrometry of transferrin can be used to diagnose congenital disorders of glycosylation (CDG) by detecting abnormal N-glycosylation due to reduced site occupancy or processing failure. Time-of-flight mass spectrometers are widely used to separate 25–45 charged ions in the m/z 1,700–3,000 range, and a summed zero-charge mass distribution is generated despite the risk of improper deconvolution. In this study, the low m/z region of the multiply-charged ion mass spectrum enabled a robust analysis of CDG. A triple quadrupole mass spectrometer, the standard instrument for newborn screening for inborn errors of metabolism, permitted the identification of the key ions characteristic of different types of CDG affecting PMM2, ALG14, SLC35A1, SLC35A2, MAN1B1 and PGM1 in the m/z 1,970–2,000 region. Charge deconvolution was used as a complementary tool for validating the findings. It was necessary to set a cutoff level for the evaluation, since small peaks indicating glycosylation failure or reduced sialylation were observed, even in control subjects. This method and workflow facilitates the implementation of MS-based analyses and the screening of CDG in clinical laboratories.

Electrospray Ionization Mass Spectrometry of Apolipoprotein CIII to Evaluate O-glycan Site Occupancy and Sialylation in Congenital Disorders of Glycosylation

Congenital disorders of glycosylation (CDG) are inherited metabolic diseases that affect the synthesis of glycoconjugates. Defects in mucin-type O-glycosylation occur independently or in combination with N-glycosylation disorders, and the profiling of the O-glycans of apolipoprotein CIII (apoCIII) by mass spectrometry (MS) can be used to support a diagnosis. The biomarkers are site occupancy and sialylation levels, which are indicated by the content of non-glycosylated apoCIII0a isoform and by the ratio of monosialylated apoCIII1 to disialylated apoCIII2 isoforms, respectively. In this report, electrospray ionization (ESI) quadrupole MS of apoCIII was used to identify these biomarkers. Among the instrumental parameters, the declustering potential (DP) induced the fragmentation of the O-glycan moiety including the Thr–GalNAc linkage, resulting in an increase in apoCIII0a ions. This incurs the risk of creating a false positive for reduced site occupancy. The apoCIII1/apoCIII2 ratio was substantially unchanged despite some dissociation of sialic acids. Therefore, appropriate DP settings are especially important when transferrin, which requires a higher DP, for N-glycosylation disorders is analyzed simultaneously with apoCIII in a single ESI MS measurement. Finally, a reference range of diagnostic biomarkers and mass spectra of apoCIII obtained from patients with SLC35A1-, TRAPPC11-, and ATP6V0A2-CDG are presented.

A homozygous ABHD16A variant causes a complex hereditary spastic paraplegia with developmental delay, absent speech, and characteristic face

Hereditary spastic paraplegia (HSP) is a genetically and clinically heterogeneous genetic disease characterized by progressive weakness and spasticity predominantly affecting the lower limbs. Complex HSP is a subset of HSP presenting with additional neuronal and/or non-neuronal phenotypes. Here, we identify a homozygous ABHD16A nonsense variant in two affected children in a Chilean family. Very recently, two groups reported patients with biallelic ABHD16A whose clinical presentation was similar to that of our patients. By reviewing the clinical features of these reports and our patients, ABHD16A-related HSP can be characterized by early childhood onset, developmental delay, intellectual disability, speech disturbance, extrapyramidal signs, psychiatric features, no sphincter control, skeletal involvement, thin corpus callosum, and high-intensity signals in white matter on T2-weighted brain MRI. In addition, our affected siblings showed a characteristic face, sleep disturbance, and nodular and hyperpigmented skin lesions, which have not previously been reported in this condition.