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Objective@#To explore the molecular basisfor a child featuring short stature, abnormal facial features and developmental delay.@*Methods@#Genomic DNA was extracted from peripheral blood samples from the child and his family members. Next-generation sequencing was carried out to screen the whole exomes of the core family. Detected variants were filtered and analyzed according to the standards and guidelines for the interpretation of sequence variants recommended by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology.@*Results@#Trio-based sequencing has identified a de novo variant c. 3593T>G (p.Val1198Gly) in the SMARCA2gene in the patient. The variant was located in the Helicase C-terminal domain and was classified as pathogenic based on the guidelines.@*Conclusion@#The patient was diagnosed with Nicolaides-Baraitser syndrome caused by SMARCA2 gene mutation.
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OBJECTIVE@#To explore the molecular basisfor a child featuring short stature, abnormal facial features and developmental delay.@*METHODS@#Genomic DNA was extracted from peripheral blood samples from the child and his family members. Next-generation sequencing was carried out to screen the whole exomes of the core family. Detected variants were filtered and analyzed according to the standards and guidelines for the interpretation of sequence variants recommended by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology.@*RESULTS@#Trio-based sequencing has identified a de novo variant c.3593T>G (p.Val1198Gly) in the SMARCA2 gene in the patient. The variant was located in the Helicase C-terminal domain and was classified as pathogenic based on the guidelines.@*CONCLUSION@#The patient was diagnosed with Nicolaides-Baraitser syndrome caused by SMARCA2 gene mutation.
Subject(s)
Child , Humans , Facies , Foot Deformities, Congenital , Genetics , Hypotrichosis , Genetics , Intellectual Disability , Genetics , Mutation , Transcription Factors , GeneticsABSTRACT
Objective To analyze the clinical and biochemical,as well as genetic characteristics of a patient with Wiedemann-Steiner syndrome (WDSTS).Methods The clinical data of a patient with WDSTS were collected.The patient was treated with recombinant human growth hormone (rhGH) combined with gonadotrophine-releasing hormone agonist (GnRHa).Blood samples of the patient and her parents were taken for whole-Exome Sequencing (WES).Relevant literatures about KMT2A mutations were reviewed.Results The 5-year old girl presented with growth retardation,with height 100 cm (-2.4 SD),torpid reaction,and facial anomalies including low hairline,thick eyebrow and hair,hypertelorism,a wide nasal bridge.She had small and puffy hands and feet,excessive hair around back of neck,bilateral forearm and lower limbs.Her GH peak level was 26.6 ng/ml during GH stimulation test.She was re-examined at the age of 10.4 years,with severe short stature (120 cm/-3.58 SD) and a Tanner stage 2 of breast development.Her bone age was found to be approximately 11.4 years.Height increased from 120 cm at the age of 10.4 years to 147.3 cm after rhGH treatment combined with GnRHa for 2.5 years.rhGH therapy alone continued for 1.1 years and a height of 150 cm was reached at the age of 14.9 years,with bone age 14 years.Gene sequencing revealed a de novo frameshift mutation (c.10051 delA,p.Thr3351 Leufs * 17) of exon 27 in KMT2A gene of the patient,but without any mutation in her parents.Through a literature review,seventy-one patients with WDSTS (including present case) presented with intellectual disability (70/71),facial anomalies (70/71),short stature (50/71),and hypertrichosis (39/71).Conclusion Patients presented with short stature,typical facial dysmorphism,intellectual disability,and hypertrichosis should be considered for WDSTS.The mutation p.Thr3351Leufs * 17 in the KMT2A gene detected in our patient is a novel mutation.This is so far the first report of WDSTS patient who was successfully treated with a combination of GH and GnRHa at the onset of puberty to improve her adult height.
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Objective Design short stature panel with gene curration strategy.Methods The gene curation process was introduced in detail.The strength of a gene-disease relationship was evaluated based on publicly available genetic and experimental evidence.This process in short stature panel design and its effect on gene selection was further demonstrated.Results After gene curation, the number of gene in list was effectively decreased from 1 276 to 705.The panel sequencing reached a diagnosis rate of 19.7% among a cohort of 371 nation-wide ascertained short stature patients.The gene curation process reduced the risk of false positive findings and decreased diagnostic cost and working hours without affecting the diagnosis rate.Conclusion Gene curation is an important step for NGS-based test and should be widely exercised.
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Objective To investigate the genetic basis of patients with intellectual disability,and to assess the application of single nucleotide polymorphisms (SNP)-array in the molecular diagnosis of intellectual disability.Methods Sixty-four patients with intellectual disability who were identified in Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region from January 2013 to June of 2015 were enrolled.Genomic DNA was extracted from peripheral blood and was analyzed with Illumina Humancyto SNP-12 300K gene array chip.All identified copy number variants (CNVs) were analyzed with references from databases such as ClinVar,DECIPHER,OMIM and DGV(Database of Genomic Variants),as well as comprehensive literature review from PubMed database to determine the pathogenicity of CNVs.Results Sixteen cases of the above 64 patients were found to have CNVs with genomic alterations,including 6 cases microdeletions/microduplications associated with known syndromes,3 cases microdeletions and microduplications with clear clinical relevance (non-syndrome),1 case numerical chromosome aberration,1 case unbalanced translocation and 5 cases CNVs of unknown clinical significance.The detection rate was 25% (16/64 cases).Among these 16 abnormalities,6 cases of them could not be detected by using karyotyping analysis because their sizes were less than 5 Mb,and the smallest detected missing fragment was 0.53 Mb.Conclusion SNP-array gene chip technique with the advantages of higher efficiency,high-resolution and good accuracy,which can be applied to the genetic diagnosis of intellectual disability.
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<p><b>OBJECTIVE</b>To explore the value of single nucleotide polymorphism array (SNP-array) for the analysis of pediatric patients with growth retardation.</p><p><b>METHODS</b>One hundred eighty one children with growth retardation were enrolled. DNA was extracted from peripheral samples from the patients, and whole genome copy number variations (CNVs) were detected using Illumina Human Cyto SNP-12. All identified CNVs were further analyzed with reference to databases including ClinGen, ClinVar, DECIPHER, OMIM and DGV as well as comprehensive review of literature from PubMed to determine their pathogenicity.</p><p><b>RESULTS</b>Forty seven patients (26%) with abnormal CNVs were detected, which included 12 known microdeletions/microduplications syndrome (26%), 10 pathogenic non-syndromic CNVs (21%), 3 numerical chromosome aberrations (6%), 3 unbalanced translocations (6%), 4 pathogenic mosaicisms (9%) and 15 cases with unknown clinical significance (32%). After excluding obvious numerical and/or structural chromosomal abnormalities, this study has detected 15 pathogenic microdeletions/microduplications sized 5 Mb or less, which may be missed by routine chromosomal karyotyping. In addition, there were 3 cases with loss of heterozygoisty (LOH) containing known or predicted imprinting genes as well as 2 cases with suspected parental consanguinity.</p><p><b>CONCLUSION</b>SNP-array technology is a powerful tool for the genetic diagnosis of children with growth disorders with advantages of high resolution and improved accuracy.</p>
Subject(s)
Adolescent , Child , Child, Preschool , Female , Humans , Infant , Male , Chromosome Aberrations , DNA Copy Number Variations , Developmental Disabilities , Diagnosis , Genetics , Karyotyping , Oligonucleotide Array Sequence Analysis , Methods , Polymorphism, Single NucleotideABSTRACT
OBJECTIVE To generate hemophilia A (HA) patient-specific inducible pluripotent stem cells (iPSCs) and induce endothelial differentiation. METHODS Tubular epithelial cells were isolated and cultured from the urine of HA patients. The iPSCs were generated by forced expression of Yamanaka factors (Oct4, Sox2, c-Myc and Klf4) using retroviruses and characterized by cell morphology, pluripotent marker staining and in vivo differentiation through teratoma formation. Induced endothelial differentiation of the iPSCs was achieved with the OP9 cell co-culture method. RESULTS Patient-specific iPSCs were generated from urine cells of the HA patients, which could be identified by cell morphology, pluripotent stem cell surface marker staining and in vivo differentiation of three germ layers. The teratoma experiment has confirmed that such cells could differentiate into endothelial cells expressing the endothelial-specific markers CD144, CD31 and vWF. CONCLUSION HA patient-specific iPSCs could be generated from urine cells and can differentiate into endothelial cells. This has provided a new HA disease modeling approach and may serve as an applicable autologous cell source for gene correction and cell therapy studies for HA.