Delineation of the adult phenotype of Coffin-Siris syndrome in 35 individuals

Coffin-Siris syndrome (CSS) is a rare multisystemic autosomal dominant disorder. Since 2012, alterations in genes of the SWI/SNF complex were identified as the molecular basis of CSS, studying largely pediatric cohorts. Therefore, there is a lack of information on the phenotype in adulthood, particularly on the clinical outcome in adulthood and associated risks. In an international collaborative effort, data from 35 individuals ≥ 18 years with a molecularly ascertained CSS diagnosis (variants in ARID1B, ARID2, SMARCA4, SMARCB1, SMARCC2, SMARCE1, SOX11, BICRA) using a comprehensive questionnaire was collected. Our results indicate that overweight and obesity are frequent in adults with CSS. Visual impairment, scoliosis, and behavioral anomalies are more prevalent than in published pediatric or mixed cohorts. Cognitive outcomes range from profound intellectual disability (ID) to low normal IQ, with most individuals having moderate ID. The present study describes the first exclusively adult cohort of CSS individuals. We were able to delineate some features of CSS that develop over time and have therefore been underrepresented in previously reported largely pediatric cohorts, and provide recommendations for follow-up.

Expanding the genetics and phenotypic spectrum of Lysine-specific demethylase 5C (KDM5C): a report of 13 novel variants

Lysine-specific demethylase 5C (KDM5C) has been identified as an important chromatin remodeling gene, contributing to X-linked neurodevelopmental disorders (NDDs). The KDM5C gene, located in the Xp22 chromosomal region, encodes the H3K4me3-me2 eraser involved in neuronal plasticity and dendritic growth. Here we report 30 individuals carrying 13 novel and one previously identified KDM5C variants. Our cohort includes the first reported case of somatic mosaicism in a male carrying a KDM5C nucleotide substitution, and a dual molecular finding in a female carrying a homozygous truncating FUCA1 alteration together with a de novo KDM5C variant. With the use of next generation sequencing strategies, we detected 1 frameshift, 1 stop codon, 2 splice-site and 10 missense variants, which pathogenic role was carefully investigated by a thorough bioinformatic analysis. The pattern of X-chromosome inactivation was found to have an impact on KDM5C phenotypic expression in females of our cohort. The affected individuals of our case series manifested a neurodevelopmental condition characterized by psychomotor delay, intellectual disability with speech disorders, and behavioral features with particular disturbed sleep pattern; other observed clinical manifestations were short stature, obesity and hypertrichosis. Collectively, these findings expand the current knowledge about the pathogenic mechanisms leading to dysfunction of this important chromatin remodeling gene and contribute to a refinement of the KDM5C phenotypic spectrum.

Variants of Novel Immunomodulatory Fc Receptor Like 5 Gene Are Associated With Multiple Sclerosis Susceptibility in the Polish Population

Fc receptors have been shown to play a role in several autoimmune diseases. We aimed to test, for the first time, whether some of the single nucleotide variants in the FCRL5 gene were associated with multiple sclerosis (MS) susceptibility and clinical manifestations in the Polish population. The case-control study included 94 individuals with MS and 160 healthy subjects. We genotyped two single nucleotide variants of the FCRL5 gene: rs2012199 and rs6679793. The age of onset, disease duration, and clinical condition of the MS subjects were analyzed. For statistical analysis, we used the chi-squared test confirmed with Fisher's exact test. We observed the significant differences in the distribution of investigated FCRL5 genotypes between MS subjects and healthy controls. The CC and CT genotypes, as well as the C allele of rs2012199, were significantly more common in the MS subjects, as were genotypes AA and AG, and allele A of rs6679793. We noted that decreased MS susceptibility was associated with the T allele rs2012199 (OR = 0.37, p = 0.0002) and G allele rs6679793 (OR = 0.6, p = 0.02). Our results support the role of the FCRL5 locus in MS predisposition and extend the evidence of its influence on autoimmunity.

Pharmacogenomics, How to Deal with Different Types of Variants in Next Generation Sequencing Data in the Personalized Medicine Area

Pharmacogenomics (PGx) is the knowledge of diverse drug responses and effects in people, based on their genomic profiles. Such information is considered as one of the main directions to reach personalized medicine in future clinical practices. Since the start of applying next generation sequencing (NGS) methods in drug related clinical investigations, many common medicines found their genetic data for the related metabolizing/shipping proteins in the human body. Yet, the employing of technology is accompanied by big obtained data, which most of them have no clear guidelines for consideration in routine treatment decisions for patients. This review article talks about different types of NGS derived PGx variants in clinical studies and try to display the current and newly developed approaches to deal with pharmacogenetic data with/without clear guidelines for considering in clinical settings.

Frequency of thrombophilia associated genes variants: population-based study

BACKGROUND

Thrombophilia is a hypercoagulable state that may have a genetic basis (inherited) or can be acquired. It is a multifactorial condition and only the mutual interactions between the environment and genes may lead to the development of clinical manifestation. This state is the main factor promoting venous (rarely arterial) thromboembolism (VTE). Inherited thrombophilia is mainly associated with two pathogenic variants in the V coagulation factor (FV) and the prothrombin (FII) genes. The aim of our study was to evaluate the frequency of two pathogenic variants in FII and FV genes as inherited thrombophilia factors in a group within the Polish population in comparison with other described populations.

METHODS

All studied groups consisted of 633 unrelated patients aged between 18 and 70. Individuals in the research group come from the Podlasie region of Poland. Genotyping of FII and FV variants was performed using the 7900HT Fast Real-Time PCR System and were genotyped by TaqMan assay.

RESULTS

The pathogenic allele frequency for A allele was 0.03 (3%) and 0.07 (7%) for FII and FV genes, respectively. The GA/AA genotypes (c.*97G > A variant) were observed in only 33 (5.03%) individuals in the studied group. Additionally, the frequency of GA/AA genotypes was over 17.4% in the coagulation factor V. Co-incidence of heterozygous genotype GA of variants FII and FV genes was observed in only 4 subjects.

CONCLUSION

The FII gene variant shown in our study is less frequent than in other European countries (about 6%). In contrast, the A allele of the FV gene occurs with a frequency similar to that of Northern, Central and South Central Europe (about 5%).

Primrose syndrome: Characterization of the phenotype in 42 patients

Primrose syndrome (PS; MIM# 259050) is characterized by intellectual disability (ID), macrocephaly, unusual facial features (frontal bossing, deeply set eyes, down‐slanting palpebral fissures), calcified external ears, sparse body hair and distal muscle wasting. The syndrome is caused by de novo heterozygous missense variants in ZBTB20. Most of the 29 published patients are adults as characteristics appear more recognizable with age. We present 13 hitherto unpublished individuals and summarize the clinical and molecular findings in all 42 patients. Several signs and symptoms of PS develop during childhood, but the cardinal features, such as calcification of the external ears, cystic bone lesions, muscle wasting, and contractures typically develop between 10 and 16 years of age. Biochemically, anemia and increased alpha‐fetoprotein levels are often present. Two adult males with PS developed a testicular tumor. Although PS should be regarded as a progressive entity, there are no indications that cognition becomes more impaired with age. No obvious genotype‐phenotype correlation is present. A subgroup of patients with ZBTB20 variants may be associated with mild, nonspecific ID. Metabolic investigations suggest a disturbed mitochondrial fatty acid oxidation. We suggest a regular surveillance in all adult males with PS until it is clear whether or not there is a truly elevated risk of testicular cancer.

Compound heterozygous IFT140 variants in two Polish families with Sensenbrenner syndrome and early onset end-stage renal disease

Background

Sensenbrenner syndrome, which is also known as cranioectodermal dysplasia (CED), is a rare, autosomal recessive ciliary chondrodysplasia characterized by a variety of clinical features including a distinctive craniofacial appearance as well as skeletal, ectodermal, liver and renal anomalies. Progressive renal disease can be life-threatening in this condition. CED is a genetically heterogeneous disorder. Currently, variants in any of six genes (IFT122, WDR35, IFT140, IFT43, IFT52 and WDR19) have been associated with this syndrome. All of these genes encode proteins essential for intraflagellar transport (IFT) a process that is required for cilium assembly, maintenance and function. Intra- and interfamilial clinical variability has been reported in CED, which is consistent with CED’s genetic heterogeneity and is indicative of genetic background effects.

Results

Two male CED patients from two unrelated Polish families were included in this study. Clinical assessment revealed distinctive clinical features of Sensenbrenner syndrome, such as dolichocephaly, shortening of long bones and early onset renal failure. Ectodermal anomalies also included thin hair, short and thin nails, and small teeth in both patients. Next generation sequencing (NGS) techniques were performed in order to determine the underlying genetic cause of the disorder using whole exome sequencing (WES) for patient 1 and a custom NGS-based panel for patient 2. Subsequent qPCR and duplex PCR analysis were conducted for both patients. Genetic analyses identified compound heterozygous variants in the IFT140 gene in both affected individuals. Both patients harbored a tandem duplication variant p.Tyr1152_Thr1394dup on one allele. In addition, a novel missense variant, p.(Leu109Pro), and a previously described p.(Gly522Glu) variant were identified in the second allele in patients 1 and 2, respectively. Segregation analysis of the variants was consistent with the expected autosomal recessive disease inheritance pattern. Both patients had severe renal failure requiring kidney transplantation in early childhood.

Conclusion

The finding of compound heterozygous IFT140 mutations in two unrelated CED patients provide further evidence that IFT140 gene mutations are associated with this syndrome. Our studies confirm that IFT140 changes in patients with CED are associated with early onset end-stage renal disease. Moreover, this report expands our knowledge of the clinical- and molecular genetics of Sensenbrenner syndrome and it highlights the importance of multidisciplinary approaches in the care of CED patients.

Salivary Gland Function, Antioxidant Defence and Oxidative Damage in the Saliva of Patients with Breast Cancer: Does the BRCA1 Mutation Disturb the Salivary Redox Profile?

Oxidative stress plays a key role in breast cancer progression. However, little is still known about the relationship between the BRCA1 mutation, the incidence of breast cancer and oral homeostasis. This is the first study to evaluate the secretory function of salivary glands, biomarkers of redox balance, and oxidative damage to proteins and lipids in the saliva of subjects with the BRCA1 mutation. Ninety eight women were enrolled in the study and allocated to four groups based on molecular DNA testing: generally healthy patients without the BRCA1 mutation, patients with breast cancer but without the BRCA1 mutation, generally healthy patients with the BRCA1 mutation, and patients with both breast cancer and the BRCA1 mutation. We demonstrated that saliva from breast cancer patients with the BRCA1 mutation is characterized by enhanced antioxidant capacity and a higher degree of oxidative damage to proteins and lipids. The BRCA1 mutation can cause a predisposition to early salivary gland dysfunction, both in patients with breast cancer and in healthy individuals, leading to a decrease in salivary proteins. Using cluster analysis, we showed that salivary peroxidase, advanced glycation end-products (AGE), total antioxidant status (TAS) and malondialdehyde (MDA) may have particular clinical significance in non-invasive diagnostics of breast cancer.

Analysis of chosen SNVs in GPC5, CD58 and IRF8 genes in multiple sclerosis patients

PURPOSE

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system with a neurodegenerative compound. Heterogenetic background of autoimmunity pathway components has been suggested in the MS pathogenesis. The main aim of our study was to evaluate the association between selected polymorphisms of theCD58, IRF8 and GPC5 genes and treatment effectiveness in a group of relapsing-remitting MS patients. This is the first study of MS patients from Podlaskie Region in the Polish population.

MATERIALS AND METHODS

The study group comprised 174 relapsing-remitting MS patients diagnosed under 40 years of age. Genotyping was performed using ready to use TaqMan assays.

RESULTS

We demonstrate a strong association of the polymorphisms with sex, age of onset and response to the treatment applied. A significant correlation was observed in the presence of allele T of rs10492503 polymorphism inGPC5 gene with sex and age of MS onset. Logistic regression analysis revealed an increased risk of the interaction of rs17445836 in IRF8 gene with male sex and the type of treatment (OR = 3.80, p < 0.05), and a decreased risk in the interaction of female sex with disease progress according to the EDSS scale (OR=-2.33, p < 0.05).

CONCLUSIONS

The analysis of the correlation between different alleles, genotypes and clinical status confirmed the interaction between the genetic factors of age of onset and response to therapy. The study suggests that genetic variants inGPC5, CD58 and IRF8 genes may be of clinical interest in MS as predictors of age of onset and response to therapy.

Mutations in SMARCB1 and in other Coffin-Siris syndrome genes lead to various brain midline defects

Mutations in genes encoding components of BAF (BRG1/BRM-associated factor) chromatin remodeling complexes cause neurodevelopmental disorders and tumors. The mechanisms leading to the development of these two disease entities alone or in combination remain unclear. We generated mice with a heterozygous nervous system-specific partial loss-of-function mutation in a BAF core component gene, Smarcb1. These Smarcb1 mutant mice show various brain midline abnormalities that are also found in individuals with Coffin–Siris syndrome (CSS) caused by SMARCB1, SMARCE1, and ARID1B mutations and in SMARCB1-related intellectual disability (ID) with choroid plexus hyperplasia (CPH). Analyses of the Smarcb1 mutant animals indicate that one prominent midline abnormality, corpus callosum agenesis, is due to midline glia aberrations. Our results establish a novel role of Smarcb1 in the development of the brain midline and have important clinical implications for BAF complex-related ID/neurodevelopmental disorders.

Why and how mutations in genes encoding BAF complex components lead to distinct disease entitites remains unresolved. In this study, authors establish the first Smarcb1 mutant mouse model with multiple brain abnormalities recapitulating human Coffin–Siris syndrome and show that one prominent midline abnormality, corpus callosum agenesis, is due to midline glia aberrations.

Association between polymorphisms of a folate - homocysteine - methionine - SAM metabolising enzyme gene and multiple sclerosis in a Polish population

BACKGROUND AND OBJECTIVES

Multiple sclerosis (MS) is a chronic inflammatory, autoimmune disease with a still unknown aetiology. The main initial mechanism of demyelination and injury to the central nervous system (CNS) appears to be inflammation. Neurotoxicity induced by homocysteine (Hcy) may be a factor affecting this process. 5,10-methylenetetrahydrofolate reductase (MTHFR) is an essential enzyme involved in Hcy metabolism. It leads to Hcy remethylation to methionine. In the present study, we aimed to investigate a possible association between two variants of MTHFR gene in patients with MS in Poland and healthy individuals.

METHODS

In this study, we genotyped 174 relapsing-remitting MS patients and 186 healthy controls using the TaqMan technique.

RESULTS AND CONCLUSIONS

It was found that, regardless of the presence of a specific allele, the gender of MS patients affects age at the time of the clinical onset of the disease: in rs1801133 for the C allele and T, the average age was 35 years for women and 29 for men (p = 0.0004; p = 0.034 respectively). Similarly for the second polymorphism rs1801131 for the A allele and C, the average age was 35 years for women and 29 for men (p = 0.001; p = 0.01 respectively). No significant allelic / genotypic frequency differences have been observed between the studied groups (c.677C > T, CT/TT p = 0.719, p = 0.262; c.1298A > C, AC/CC of p = 0.686; p = 0.66). We found no association between polymorphisms of a folate-homocysteine-methionine-SAM metabolising gene enzyme and multiple sclerosis in a Polish population.

The FOXP3 rs3761547 Gene Polymorphism in Multiple Sclerosis as a Male-Specific Risk Factor

The FOXP3 gene encodes a transcription factor and is predominantly expressed in the CD4+CD25+ regulatory T cells which plays a pivotal role in the maintenance of immune homeostasis. The defect of FOXP3 gene may provide a critical link between autoimmunity and immune deficiency. The purpose of our study was to evaluate the association of chosen polymorphisms of FOXP3 gene (rs3761549, rs3761548, rs3761547) with different clinical multiple sclerosis (MS) data of our relapsing-remitting groups of patients and in control group. The study was performed on a group consisting of 174 relapsing-remitting MS patients, diagnosed under 40 years of life, and 174 healthy volunteers. Genotyping was performed using a real-time PCR-based method by TaqMan Assays. Significant differences in distribution of allele C rs3761547 were found in male MS patients in comparison to the male healthy group (p = 0.046, OR 1.95, CI 95%). No association between MS and the other two polymorphisms was observed in males and females of both studied groups. Our data may suggest that FOXP3 rs3761547 gene polymorphism are related notably with the increased risk of MS development in males patients. To our knowledge this is the first study which indicates gender-specific relation between rs3761547 FOXP3 gene polymorphism and multiple sclerosis.

Mapping of breakpoints in balanced chromosomal translocations by shallow whole-genome sequencing points to EFNA5, BAHD1 and PPP2R5E as novel candidates for genes causing human Mendelian disorders

BACKGROUND

Mapping the breakpoints in de novo balanced chromosomal translocations (BCT) in symptomatic individuals provides a unique opportunity to identify in an unbiased way the likely causative genetic defect and thus find novel human disease candidate genes. Our aim was to fine-map breakpoints of de novo BCTs in a case series of nine patients.

METHODS

Shallow whole-genome mate pair sequencing (SGMPS) together with long-range PCR and Sanger sequencing. In one case (BCT disrupting BAHD1 and RET) cDNA analysis was used to verify expression of a fusion transcript in cultured fibroblasts.

RESULTS

In all nine probands 11 disrupted genes were found, that is, EFNA5, EBF3, LARGE, PPP2R5E, TXNDC5, ZNF423, NIPBL, BAHD1, RET, TRPS1 and SLC4A10. Five subjects had translocations that disrupted genes with so far unknown (EFNA5, BAHD1, PPP2R5E, TXNDC5) or poorly delineated impact on the phenotype (SLC4A10, two previous reports of BCT disrupting the gene). The four genes with no previous disease associations (EFNA5, BAHD1, PPP2R5E, TXNDC5), when compared with all human genes by a bootstrap test, had significantly higher pLI (p<0.017) and DOMINO (p<0.02) scores indicating enrichment in genes likely to be intolerant to single copy damage. Inspection of individual pLI and DOMINO scores, and local topologically associating domain structure suggested that EFNA5, BAHD1 and PPP2R5E were particularly good candidates for novel disease loci. The pathomechanism for BAHD1 may involve deregulation of expression due to fusion with RET promoter.

CONCLUSION

SGMPS in symptomatic carriers of BCTs is a powerful approach to delineate novel human gene-disease associations.

Breast cancer in an 18-year-old female: A fatal case report and literature review

Breast cancer (BC) is the most frequent malignancy in both pre- and postmenopausal women. However, it is exceedingly rare in very young patients, and especially in adolescents. Herein, we report a case of an 18-year-old female diagnosed with invasive BC. The proband had been found to be negative for BC in close family members. A common BC genetic screening test for the Polish population did not detect any known founder mutations in the BRCA1 gene. Further evaluation identified a p.Ile157Thr (I157T) mutation in the CHEK2 gene, a p.Ala1991Val (A1991V) variant of unknown significance in the BRCA2 gene, p.Lys751Gln (K751Q) variant in the XPD (ERCC2) gene, and a homozygous p.Glu1008Ter (E1008*) mutation in the NOD2 gene. No other mutation had been found by next generation sequencing in major BC high-risk susceptibility genes BRCA1, BRCA2, as well as 92 other genes. To date, all these found alterations have been considered as low to moderate risk factors in the general population and moderate risk factors in younger women (<35 years of age). There are no previous articles relating low and moderate risk gene mutations to very young onset (below 20 years) BC with a fatal outcome. In our patient, a possible cumulative or synergistic risk effect for these 4 alterations, and a mutation in the NOD2 gene in particular, of which both presumably healthy parents were found to be carriers, is suggested.

The Tatton-Brown-Rahman Syndrome: A clinical study of 55 individuals with de novo constitutive DNMT3A variants

Tatton-Brown-Rahman syndrome (TBRS; OMIM 615879), also known as the DNMT3A-overgrowth syndrome, is an overgrowth intellectual disability syndrome first described in 2014 with a report of 13 individuals with constitutive heterozygous DNMT3A variants. Here we have undertaken a detailed clinical study of 55 individuals with de novoDNMT3A variants, including the 13 previously reported individuals. An intellectual disability and overgrowth were reported in >80% of individuals with TBRS and were designated major clinical associations. Additional frequent clinical associations (reported in 20-80% individuals) included an evolving facial appearance with low-set, heavy, horizontal eyebrows and prominent upper central incisors; joint hypermobility (74%); obesity (weight ³2SD, 67%); hypotonia (54%); behavioural/psychiatric issues (most frequently autistic spectrum disorder, 51%); kyphoscoliosis (33%) and afebrile seizures (22%). One individual was diagnosed with acute myeloid leukaemia in teenage years. Based upon the results from this study, we present our current management for individuals with TBRS

WRN Mutation Update: Mutation Spectrum, Patient Registries, and Translational Prospects

Werner syndrome (WS) is a rare autosomal recessive disorder characterized by a constellation of adult onset phenotypes consistent with an acceleration of intrinsic biological aging. It is caused by pathogenic variants in the WRN gene, which encodes a multifunctional nuclear protein with exonuclease and helicase activities. WRN protein is thought to be involved in optimization of various aspects of DNA metabolism, including DNA repair, recombination, replication, and transcription. In this update, we summarize a total of 83 different WRN mutations, including eight previously unpublished mutations identified by the International Registry of Werner Syndrome (Seattle, WA) and the Japanese Werner Consortium (Chiba, Japan), as well as 75 mutations already reported in the literature. The Seattle International Registry recruits patients from all over the world to investigate genetic causes of a wide variety of progeroid syndromes in order to contribute to the knowledge of basic mechanisms of human aging. Given the unusually high prevalence of WS patients and heterozygous carriers in Japan, the major goal of the Japanese Consortium is to develop effective therapies and to establish management guidelines for WS patients in Japan and elsewhere. This review will also discuss potential translational approaches to this disorder, including those currently under investigation.

PEHO Syndrome May Represent Phenotypic Expansion at the Severe End of the Early-Onset Encephalopathies

BACKGROUND

Progressive encephalopathy with edema, hypsarrhythmia and optic atrophy (PEHO) syndrome is a distinct neurodevelopmental disorder. Patients without optic nerve atrophy and brain imaging abnormalities but fulfilling other PEHO criteria are often described as a PEHO-like syndrome. The molecular bases of both clinically defined conditions remain unknown in spite of the widespread application of genome analyses in both clinic and research.

METHODS

We enrolled two patients with a prior diagnosis of PEHO and two individuals with PEHO-like syndrome. All four individuals subsequently underwent whole-exome sequencing and comprehensive genomic analysis.

RESULTS

We identified disease-causing mutations in known genes associated with neurodevelopmental disorders including GNAO1 and CDKL5 in two of four individuals. One patient with PEHO syndrome and a de novoGNAO1 mutation was found to have an additional de novo mutation in HESX1 that is associated with optic atrophy.

CONCLUSIONS

We hypothesize that PEHO and PEHO-like syndrome may represent a severe end of the spectrum of the early-onset encephalopathies and, in some instances, its complex phenotype may result from an aggregated effect of mutations at two loci.

Expression of the energy substrate transporters in uterine fibroids

Proliferating cells exhibit accelerated rates of substrate utilization, favoring glucose over fatty acids (FA's) oxidation. Protein-mediated transport is thought to play a predominant role in facilitating either glucose or FA routing into the cells. In the present study, we examined the expression of glucose transporters (GLUT-1, GLUT-4) and fatty acids transporters (FAT/CD36, FATP-1, FATP-4) at transcript and protein levels as well as cytosolic fatty acid binding proteins (H-FABP, ACBP) in human fibroids (n=74, size up to 3cm diameter) and compared with pair-matched healthy myometrium. Additionally lipid content (diacylglycerols, triacylglycerols and ceramide) was estimated by gas liquid chromatography (GLC). Uterine fibroids displayed decreased expression of both FAT/CD36 and FATP-1 proteins along with lower diacylglycerol (DAG) and triacylglycerol (TAG) content as compared to healthy pair-matched myometrium. The expression of glucose transport proteins (GLUT-4 and GLUT-1) remained relatively constant, although the higher expression of GLUT-1 in uterine fibroids did not reach the minimum significance threshold (p=0.056). However, no change in either cytochrome c oxidase (COX IV) or hydroxyacyl-CoA dehydrogenase (HADHSC) was observed and these data confirm a possible metabolic shift favoring glucose utilization over fatty acid oxidation in human uterine fibroids.

The smallest de novo deletion of 20q11.21-q11.23 in a girl with feeding problems, retinal dysplasia, and skeletal abnormalities

We report on a de novo interstitial deletion of 20q11.21-q11.23 in a 2-year-old girl with a set of dysmorphic features, cleft palate, heart defect, severe feeding problems, failure to thrive, developmental delay, preaxial polydactyly (right thumb), and retinal dysplasia. Interstitial microdeletions of the long arm of chromosome 20 are rare. Exclusively rare are proximal microdeletions involving 20q11-q12 region. Our patient is the fourth described so far and has the smallest deleted region 20q11.21-q11.23 of 5.7 Mb. The defined clinical phenotype of our patient is very similar to previously published cases and confirms the existence of retinal dysplasia and skeletal abnormalities as a part of phenotypic spectrum for deletion 20q11-q12. Description of four similar patients, including two almost identical, suggests a new distinct, phenotypicaly recognizable microdeletion syndrome associated with the loss of 20q11-q12 region.

Loss-of-function mutations in TBC1D20 cause cataracts and male infertility in blind sterile mice and Warburg micro syndrome in humans

blind sterile (bs) is a spontaneous autosomal-recessive mouse mutation discovered more than 30 years ago. Phenotypically, bs mice exhibit nuclear cataracts and male infertility; genetic analyses assigned the bs locus to mouse chromosome 2. In this study, we first positionally cloned the bs locus and identified a putative causative mutation in the Tbc1d20 gene. Functional analysis established the mouse TBC1D20 protein as a GTPase-activating protein (GAP) for RAB1 and RAB2, and bs as a TBC1D20 loss-of-function mutation. Evaluation of bs mouse embryonic fibroblasts (mEFs) identified enlarged Golgi morphology and aberrant lipid droplet (LD) formation. Based on the function of TBC1D20 as a RABGAP and the bs cataract and testicular phenotypes, we hypothesized that mutations in TBC1D20 may contribute to Warburg micro syndrome (WARBM); WARBM constitutes a spectrum of disorders characterized by eye, brain, and endocrine abnormalities caused by mutations in RAB3GAP1, RAB3GAP2, and RAB18. Sequence analysis of a cohort of 77 families affected by WARBM identified five distinct TBC1D20 loss-of-function mutations, thereby establishing these mutations as causative of WARBM. Evaluation of human fibroblasts deficient in TBC1D20 function identified aberrant LDs similar to those identified in the bs mEFs. Additionally, our results show that human fibroblasts deficient in RAB18 and RAB3GAP1 function also exhibit aberrant LD formation. These findings collectively indicate that a defect in LD formation/metabolism may be a common cellular abnormality associated with WARBM, although it remains unclear whether abnormalities in LD metabolism are contributing to WARBM disease pathology.

A natural history of a child with monosomy 5p syndrome (Cat-cry/Cri-du-chat syndrome) during the 18 years of follow-up

A record of a natural history of a long-term case study devoted to monosomy 5p (Cat-cry/Cri-du-chat) syndrome has been described rarely. Knowledge on the range of the changes in phenotype attributable to advancing age can be useful in clinical diagnosis of monosomy 5p at the different developmental stages, including adolescence, as well in prognosis for genetic counseling. In this case a detailed analysis of the morphologic phenotype in a girl with del(5)(p13.3) observed from 4 months to 18 years of age is reported. The comparative analysis of the girl's phenotype in different developmental stages has revealed that microcephaly, flat occipital region, face asymmetry, wide spaced palpebral fissures, epicanthic folds, small mouth fissure, thin mucous lip, small and low set ears and short IV metacarpals has not changed with advancing age. However, facial asymmetry was more evident, frontal tubers were less prominent, nasal root and back became prominent nasal back became elongated, the subnasal region was shorter and marked malocclusion appeared.