Patient 1, a 3-year-6-month-old male, presented with feeding difficulties and delayed motor development. He exhibited poor responsiveness at birth, weak crying, intellectual and motor delays, low immunity, recurrent respiratory infections, hypotonia of the limbs, and distinctive facial features (low-set ears, double chin, and high arched palate), as well as a single transverse palmar crease on the right hand. Genetic testing revealed a c.1096C>T heterozygous variant in the SMARCB1 gene. Patient 2, a 3-year-old male, presented with developmental delay and distinctive facial features. Genetic testing identified the same pathogenic mutation as in Patient 1. The two patients are unrelated, and clinical phenotyping and genetic testing confirmed both cases as Coffin-Siris syndrome type 3. Coffin-Siris syndrome is a rare genetic disorder, and early genetic testing can aid in diagnosis.
Child, Preschool ; Humans ; Male ; Abnormalities, Multiple/genetics* ; Chromosomal Proteins, Non-Histone/genetics* ; Ear/abnormalities* ; Face/abnormalities* ; Hand Deformities, Congenital/genetics* ; Intellectual Disability/genetics* ; Micrognathism/genetics* ; Mutation ; Neck/abnormalities*

OBJECTIVE: To explore the genetic basis for two unrelated patients with global developmental delay and coarse facial features. METHODS: Clinical data and family history of the two pedigrees were collected. Whole exome sequencing and Sanger sequencing were carried out to detect potential variants. RESULTS: The two patients have presented with global developmental delay, coarse facies, muscular hypotonia, congenital heart disease, and pectus excavatum, and were found to harbor two de novo loss-of-function variants of the ARID1B gene, namely c.3586delC (p.Gln1196Serfs*15) and c.4954_4957delACGT (p.Thr1652Glyfs*31). Both variants were unreported previously. CONCLUSION The nonsense variants of the ARID1B gene probably underlay the etiology in these patients. Above finding has enriched the genotypic and phenotypic spectrum of the disease and provided a basis for prenatal diagnosis.
Abnormalities, Multiple ; China ; DNA-Binding Proteins/genetics* ; Face/abnormalities* ; Facies ; Hand Deformities, Congenital/genetics* ; Humans ; Intellectual Disability/genetics* ; Micrognathism/genetics* ; Neck/abnormalities* ; Transcription Factors/genetics*

OBJECTIVE: To explore the genetic basis for two Chinese pedigrees affected with Coffin-Siris syndrome (CSS). METHODS: Whole exome sequencing (WES) was carried out for the probands. Candidate variants were verified by Sanger sequencing of the probands and their family members. RESULTS: The two probands were respectively found to harbor a heterozygous c.5467delG (p.Gly1823fs) variant and a heterozygous c.5584delA (p.Lys1862fs) variant of the ARID1B gene, which were both of de novo in origin and unreported previously. Based on the guidelines of American College of Medical Genetics and Genomics, both variants were predicted to be pathogenic (PVS1+PS2+PM2). CONCLUSION The c.5467delG (p.Gly1823fs) and c.5545delA (p.Lys1849fs) variants of the ARID1B genes probably underlay the CSS in the two probands. Above results have enabled genetic counselling and prenatal diagnosis for the pedigrees.
Abnormalities, Multiple ; China ; DNA-Binding Proteins/genetics* ; Face/abnormalities* ; Hand Deformities, Congenital ; Humans ; Intellectual Disability ; Micrognathism ; Neck/abnormalities* ; Pedigree ; Transcription Factors/genetics*

OBJECTIVETo identify the genetic cause for a 11-year-old Chinese boy with Meier-Gorlin syndrome (MGS).

METHODSChromosomal microarray analysis (CMA) was used to detect potential variations, while whole exome sequencing (WES) was used to identify sequence variants. Sanger sequencing was used to confirm the suspected variants.

RESULTSThe boy has featured short stature, microtia, small patella, slender body build, craniofacial anomalies, and small testes with normal gonadotropin. A complete uniparental disomy of chromosome 16 was revealed by CMA. WES has identified a novel homozygous mutation c.67A>G (p.Lys23Glu) in ORC6 gene mapped to chromosome 16. As predicted by Alamut functional software, the mutation may affect the function of structural domain of the ORC6 protein.

CONCLUSIONThe patient is probably the first diagnosed MGS case in China, who carried a novel homozygous mutation of the ORC6 gene and uniparental disomy of chromosome 16. The effect of this novel mutation on the growth and development needs to be further investigated.

Base Sequence ; Child ; Chromosomes, Human, Pair 16 ; genetics ; Congenital Microtia ; genetics ; Family Health ; Fathers ; Growth Disorders ; genetics ; Heterozygote ; Humans ; Male ; Micrognathism ; genetics ; Mutation ; Origin Recognition Complex ; genetics ; Patella ; abnormalities ; Polymerase Chain Reaction ; methods ; Sequence Analysis, DNA ; methods ; Uniparental Disomy ; genetics