OBJECTIVE: To explore the genotype-phenotype correlation of a patient with cardio-facio-cutaneous syndrome (CFCS) due to variant of the MAP2K1 gene. METHODS: DNA was extracted from peripheral blood samples of the infant and his parents and subjected to whole exome sequencing. Candidate variant was verified by Sanger sequencing. RESULTS: The patient had typical CFCS facies and developmental delay, and was found to harbor a de novo heterozygous c.389A>G (p.Tyr130Cys) missense variant in exon 3 of the MAP2K1 gene. Based on the American college of Medical Genetics and Genomics guidelines, this variant was classified as likely pathogenic. CONCLUSION This patient has differed from previously reported cases by having no cardiac anomaly or seizures but typical facial features and skin abnormalities accompanied by growth retardation, intellectual impairment, and urinary malformation. It has therefore enriched the phenotypic spectrum of CFCS due to variants of the MAP2K1 gene.
Ectodermal Dysplasia/genetics* ; Facies ; Failure to Thrive/genetics* ; Heart Defects, Congenital ; Humans ; MAP Kinase Kinase 1/genetics* ; Mutation

OBJECTIVE: To explore the genetic basis of three children with unexplained mental retardation/developmental delay. METHODS: Peripheral venous blood samples were collected for routine G-banding karyotyping analysis and chromosomal microarray analysis (CMA). Whole exome sequencing (WES) was also carried out for patient 3. RESULTS: The karyotypes of the 3 children were normal. The result of CMA analysis of patient 1 was arr[GRCh37]: 2q22/3(145 128 071-145 159 029)×1, with a 31 kb deletion, which was predicted to be a pathogenic copy number variation. The deletion has involved exons 8 to 10 of the ZEB2 gene. Patient 2 was arr[hg19]:2q22.3 (145 071 457-146 881 759)×1, with a 1.81 Mb deletion involving the ZEB2 and GTDC1 genes. Patient 3 was arr[GRCh37]: 9p23p23(11 698 261-12 106 261)×1, with a 408 kb deletion containing no disease-associated gene. WES has identified a c.2102C>A (p.Ser701*) variant in exon 8 of the ZEB2 gene, which was included in ClinVar database and rated as pathogenic, and verified by Sanger sequencing as a de novo variant. CONCLUSION For the substantial clinical and genetic heterogeneity of Mowat-Wilson-syndrome, CMA and WES are helpful to identify the etiology of children with developmental delay/mental retardation of unknown causes, particularly those with peculiar facial features and multiple congenital malformations.
Child ; DNA Copy Number Variations ; Facies ; Glycosyltransferases/genetics* ; Hirschsprung Disease ; Humans ; Intellectual Disability/genetics* ; Microcephaly/genetics*