To describe a case of prenatal diagnosis of Freeman-Sheldon syndrome based on ultrasound findings and complete fetal exome sequencing.
A 33-year-old patient currently on treatment for hypothyroidism in whom a 19-week detailed anatomical ultrasound scan showed fetal deformities in more than two body areas (upper and lower limbs), suggesting a diagnosis of arthrogryposis. Genetic counseling was provided and amniocentesis was performed at 20 weeks for fluorescence in situ hybridization (FISH) analysis and complete fetal exome sequencing, with the latter allowing the identification of a heterozygous pathogenic variant of the MYH3 gene which is associated with type 2A distal arthrogryposis.
Complete fetal exome sequencing was a key factor in identifying the MYH3 gene mutation and confirmed that the deformities seen on ultrasound were associated with type 2A distal arthrogryposis. It is important to perform complete fetal exome sequencing in cases of joint malformations seen on prenatal ultrasound.
describir un caso de diagnóstico prenatal de síndrome de Freeman-Sheldon mediante hallazgos ecográficos y secuenciación completa del exoma fetal.
mujer de 33 años, con antecedentes de hipotiroidismo en tratamiento, a quien en semana 19 se realizó ecografía de detalle anatómico, en la cual se observaron deformidades en el feto en más de dos áreas corporales (extremidades superiores e inferiores), sugiriendo el diagnóstico de artrogriposis. Posteriormente, se brindó asesoría genética y se realizó amniocentesis en semana 20 de gestación, con análisis de la hibridación in situ por fluorescencia, seguido de secuenciación completa del exoma fetal. Este último examen permitió identificar una variante patogénica heterocigota en el gen MYH3, la cual se asocia con la artrogriposis distal tipo 2A.
la realización de la secuenciación completa de exoma fetal es un factor clave para identificar la mutación del gen MYH3, y confirma que las deformidades evidenciadas por ultrasonido estaban relacionadas con la artrogriposis distal tipo 2A. Es importante hacer la secuenciación de exoma fetal en fetos que muestren hallazgos de malformaciones articulares en el ultrasonido prenatal.

Increasingly, next-generation sequencing (NGS) is becoming an invaluable tool in the diagnosis of unexplained acute neurological disorders, such as acute encephalopathy/encephalitis. Here, we describe a brief series of pediatric patients who presented at the pediatric intensive care unit with severe acute encephalopathy, initially suspected as infectious or inflammatory but subsequently diagnosed with a monogenic disorder. Rapid exome sequencing was performed during the initial hospitalization of three unrelated patients, and results were delivered within 7-21 days. All patients were previously healthy, 1.5-3 years old, of Muslim Arab descent, with consanguineous parents. One patient presenting with acute necrotizing encephalopathy (ANEC). Her sister presented with ANEC one year prior. Exome sequencing was diagnostic in all three patients. All were homozygous for pathogenic and likely-pathogenic variants associated with recessive disorders; MOCS2, NDUFS8 and DBR1. Surprisingly, the initial workup was not suggestive of the final diagnosis. This case series demonstrates that the use of rapid exome sequencing is shifting the paradigm of diagnostics even in critical care situations and should be considered early on in children with acute encephalopathy. A timely diagnosis can direct initial treatment as well as inform decisions regarding long-term care.

Severe combined immunodeficiency (SCID) is a group of fatal primary immunodeficiencies characterized by the severe impairment of T-cell differentiation. IL7R deficiency is a rare form of SCID that usually presents in the first months of life with severe and opportunistic infections, failure to thrive, and a high risk of mortality unless treated. Although recent improvements in early diagnosis have been achieved through newborn screening, few IL7R-related SCID patients had been reported in the Chinese population.
Here, we retrospectively analyzed a case of SCID in a 5-month-old girl with symptoms, including severe T-cell depletion, recurrent fever, oral ulcers, pneumonia, hepatosplenomegaly, bone marrow hemophagocytosis, and bacterial and viral infections. Whole-exome sequencing (WES), quantitative PCR (qPCR), and chromosome microarray analysis (CMA) were performed to identify the patient\'s genetic etiology. We identified a 268 kb deletion and a splicing variant, c.221 + 1G > A, in the proband. These two variants of IL7R were inherited from the father and mother.
To our knowledge, this is the first report of whole IL7R gene deletion in combination with a pathogenic splicing variant in a patient with SCID. This deletion also expands the pathogenic variation spectrum of SCID caused by IL7R. The incorporation of exome-based copy number variant analysis makes WES a powerful molecular diagnostic technique for the clinical diagnosis of pediatric patients.

Timely diagnosis of persistent neonatal hypoglycemia is critical to prevent neurological sequelae, but diagnosis is complicated by the heterogenicity of the causes. We discuss two cases at separate institutions in which clinical management was fundamentally altered by the results of molecular genetic testing. In both patients, critical samples demonstrated hypoketotic hypoglycemia and a partial glycemic response to glucagon stimulation, thereby suggesting hyperinsulinism (HI). However, due to rapid genetic testing, both patients were found to have deoxyguanosine kinase (DGUOK)-related mitochondrial DNA depletion syndrome, an unexpected diagnosis. Patients with this disease typically present with either hepatocerebral disease in the neonatal period or isolated hepatic failure in infancy. The characteristic features involved in the hepatocerebral form of the disease include lactic acidosis, hypoglycemia, cholestasis, progressive liver failure, and increasing neurologic dysfunction. Those with isolated liver involvement experience hepatomegaly, cholestasis, and liver failure. Although liver transplantation is considered, research has demonstrated that for patients with DGUOK-related mitochondrial DNA depletion syndrome and neurologic symptoms, early demise occurs. Our report advocates for the prompt initiation of genetic testing in patients presenting with persistent neonatal hypoglycemia and for the incorporation of mitochondrial DNA depletion syndromes in the differential diagnosis of HI.

BACKGROUND: Dyschromatosis universalis hereditaria (DUH) is an uncommon form of pigmented genodermatosis that is typically inherited autosomally and dominantly. In the previous study, the pathogenic genes of DUH have been identified in ATP-binding cassette subfamily B, member 6 and SASH1. However, the mutational screening of the causative gene remains incomplete and still lacks sufficient proof in the etiology.
METHODS: A 2-generation Chinese family clinically diagnosed with DUH were enrolled. They showed pigmented spots from their childhood and came to the hospital for medical advice and genetic analysis. We found a novel mutation c.1757T > C (p.I586T) of SASH1 in 3 affected family members by whole-exome sequencing.
METHODS: Genetic outcomes and clinical examinations confirmed the diagnosis of DUH in 3 family members with lentiginous syndrome.
RESULTS: Using whole-exome sequencing and sanger sequencing technologies, we identified a novel mutation c.1757T > C (p.I586T) of SASH1 that co-segregated in 3 afflicted family members but not in the normal individuals. Significantly, c.1757T > C (p.I586T) is a novel mutation which had not been previously reported. The same codon position in SASH1 (c.1758C > G, p.I586M) has been reported in a Japanese man, and he showed identical phenotype compared to our study participants.
CONCLUSIONS: Our study broadens the spectrum of DUH mutations and provides more genetic characteristics of DUH in understanding its etiology. Furthermore, we demonstrated the diagnostic accuracy of whole-exome sequencing for inherited skin diseases and provided new information for etiological study.

UNASSIGNED: Childhood colorectal cancers are extremely rare and so is Osteochondromatosis. Both diseases do not have epidemiological records in African countries. The aim of this report is to present a rare coexistence of CRC and multiple enchondromas in a child.
METHODS: A case of a 12-year-old boy who presented with a large bowel obstruction secondary to an advanced tumor of the descending colon. He was also diagnosed with multiple osteochondromas affecting legs, arms, ribs, scapula, clavicle and pelvis. No positive family history was recorded. An urgent left hemicolectomy and diverting transverse colostomy was done. The colon can as stage IIIB and the patient received adjuvant chemotherapy. After 8 months of follow up, the colostomy was successfully reversed without any endoscopic signs of tumor growth or distant metastasis.
UNASSIGNED: Colorectal cancer in childhood is rare. It may present with aggressive histological subtypes in children as compared to adults. There is little to no reports on the coexistence of colorectal cancer and multiple Osteochondromatosis. Microsatellite instability in DNA tumor is common in Colon Cancer and variety of mutations of EXT-1 and EXT-2 genes goes with Enchondromatosis.
CONCLUSIONS: The coexistence of two rare conditions is the remarkable issue in this case report. There are no prior reports in literature. Further genomic sequencing maybe required to better understand this coexistence.

BACKGROUND: Retinitis pigmentosa is a group of rare hereditary retinal dystrophy diseases that lead to difficulty seeing at night, progressive loss of peripheral field vision (tunnel vision), and eventual loss of central vision. However, a genetic cause cannot be determined in approximately 60% of cases.
METHODS: Two non-consanguineous Yi minority ethnic group families who have a 6.4-year-old boy and a 0.5-year-old boy, respectively, were recruited for genetic diagnosis. Here, we used whole-exome sequencing to detect mutations in the genes of the probands of the retinitis pigmentosa families, and Sanger sequencing to confirm the causal mutations identified by whole exome sequencing. In addition, we report two cases with retinitis pigmentosa caused by RDH12 (c.524C > T) and PRPF4 (c.1273G > A) pathogenic mutations.
CONCLUSIONS: These results might extend the mutation spectrum of known retinitis pigmentosa genes and give these two Yi minority ethnic group families from Yunnan more precise genetic counseling and more specific prognoses.

Variation in genes involved in ethanol metabolism has been shown to influence risk for alcohol dependence (AD) including protective loss of function alleles in ethanol metabolizing genes. We therefore hypothesized that people with severe AD would exhibit different patterns of rare functional variation in genes with strong prior evidence for influencing ethanol metabolism and response when compared to genes not meeting these criteria.
Leverage a novel case only design and Whole Exome Sequencing (WES) of severe AD cases from the island of Ireland to quantify differences in functional variation between genes associated with ethanol metabolism and/or response and their matched control genes.
First, three sets of ethanol related genes were identified including those a) involved in alcohol metabolism in humans b) showing altered expression in mouse brain after alcohol exposure, and altering ethanol behavioral responses in invertebrate models. These genes of interest (GOI) sets were matched to control gene sets using multivariate hierarchical clustering of gene-level summary features from gnomAD. Using WES data from 190 individuals with severe AD, GOI were compared to matched control genes using logistic regression to detect aggregate differences in abundance of loss of function, missense, and synonymous variants, respectively.
Three non-independent sets of 10, 117, and 359 genes were queried against control gene sets of 139, 1522, and 3360 matched genes, respectively. Significant differences were not detected in the number of functional variants in the primary set of ethanol-metabolizing genes. In both the mouse expression and invertebrate sets, we observed an increased number of synonymous variants in GOI over matched control genes. Post-hoc simulations showed the estimated effects sizes observed are unlikely to be under-estimated.
The proposed method demonstrates a computationally viable and statistically appropriate approach for genetic analysis of case-only data for hypothesized gene sets supported by empirical evidence.

The etiology of biliary atresia (BA) is unknown, but recent studies suggest a role for rare protein-altering variants (PAVs). Exome sequencing data from the National Birth Defects Prevention Study on 54 child-parent trios, one child-mother duo, and 1513 parents of children with other birth defects were analyzed. Most (91%) cases were isolated BA. We performed (1) a trio-based analysis to identify rare de novo, homozygous, and compound heterozygous PAVs and (2) a case-control analysis using a sequence kernel-based association test to identify genes enriched with rare PAVs. While we replicated previous findings on PKD1L1, our results do not suggest that recurrent de novo PAVs play important roles in BA susceptibility. In fact, our finding in NOTCH2, a disease gene associated with Alagille syndrome, highlights the difficulty in BA diagnosis. Notably, IFRD2 has been implicated in other gastrointestinal conditions and warrants additional study. Overall, our findings strengthen the hypothesis that the etiology of BA is complex.

Genetics of epilepsy are highly heterogeneous and complex. Lesions detected involve genes encoding various types of channels, transcription factors, and other proteins implicated in numerous cellular processes, such as synaptogenesis. Consequently, a wide spectrum of clinical presentations and overlapping phenotypes hinders differential diagnosis and highlights the need for molecular investigations toward delineation of underlying mechanisms and final diagnosis. Characterization of defects may also contribute valuable data on genetic landscapes and networks implicated in epileptogenesis.
This study reports on genetic findings from exome sequencing (ES) data of 107 patients with variable types of seizures, with or without additional symptoms, in the context of neurodevelopmental disorders.
Multidisciplinary evaluation of ES, including ancillary detection of copy number variants (CNVs) with the ExomeDepth tool, supported a definite diagnosis in 59.8% of the patients, reflecting one of the highest diagnostic yields in epilepsy.
Emerging advances of next-generation technologies and \'in silico\' analysis tools offer the possibility to simultaneously detect several types of variations. Wide assessment of variable findings, specifically those found to be novel and least expected, reflects the ever-evolving genetic landscape of seizure development, potentially beneficial for increased opportunities for trial recruitment and enrollment, and optimized, even personalized, medical management.