OBJECTIVE: To explore the clinical features and genetic etiology of two children with intellectual developmental disorder and microcephaly with pontine and cerebellar hypoplasia (MICPCH). METHODS: Two children with MICPCH who were presented at the Henan Provincial People's Hospital between April 2019 and December 2021 were selected as the study subjects. Clinical data of the two children were collected, along with peripheral venous blood samples of them and their parents, and amniotic fluid sample of the mother of child 1. Whole exome sequencing (WES), array-comparative genomic hybridization (aCGH) and real-time quantitative PCR (qPCR) were carried out for the children, their parents and the fetus. The pathogenicity of candidate variants were evaluated. RESULTS: Child 1 was a 6-year-old girl featuring motor and language delay, whilst child 2 was a 4.5-year-old girl mainly featuring microcephaly and mental retardation. WES revealed that child 2 has harbored a 158.7 kb duplication in Xp11.4 (chrX: 41446160_41604854), which has encompassed exons 4~14 of the CASK gene. The same duplication was not found in either of her parents. aCGH revealed that child 1 has harbored a 29 kb deletion at Xp11.4 (chrX: 41637892_41666665), which encompassed exon 3 of the CASK gene. The same deletion was not found in either of her parents and the fetus. The above results were confirmed by qPCR assay. Above deletion and duplication were not found in the ExAC, 1000 Genomes and gnomAD databases. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were rated as likely pathogenic (PS2+PM2_Supporting). CONCLUSION The deletion of exon 3 and duplication of exons 4~14 of the CASK gene probably underlay the pathogenesis of MICPCH in these two children, respectively.
Humans ; Child ; Female ; Child, Preschool ; Microcephaly/genetics* ; Developmental Disabilities/genetics* ; Intellectual Disability/complications* ; Comparative Genomic Hybridization ; Mutation

OBJECTIVE: To analyze the clinical phenotype and genetic basis of a child with Alazami syndrome (AS). METHODS: A child who presented at Tianjin Children's Hospital on June 13, 2021 was selected as the study subject. The child was subjected to whole exome sequencing (WES), and candidate variants were verified by Sanger sequencing. RESULTS: WES revealed that the child has harbored two frameshifting variants of the LARP7 gene, namely c.429_430delAG (p.Arg143Serfs*17) and c.1056_1057delCT (p.Leu353Glufs*7), which were verified by Sanger sequencing to be respectively inherited from his father and mother. CONCLUSION The compound heterozygous variants of the LARP7 gene probably underlay the pathogenesis in this child.
Female ; Humans ; Dwarfism/genetics* ; Exome Sequencing ; Intellectual Disability/genetics* ; Microcephaly ; Mothers ; Mutation ; Male ; Child

Brain size abnormality is correlated with an increased frequency of autism spectrum disorder (ASD) in offspring. Genetic analysis indicates that heterozygous mutations of the WD repeat domain 62 (WDR62) are associated with ASD. However, biological evidence is still lacking. Our study showed that Wdr62 knockout (KO) led to reduced brain size with impaired learning and memory, as well as ASD-like behaviors in mice. Interestingly, Wdr62 Nex-cKO mice (depletion of WDR62 in differentiated neurons) had a largely normal brain size but with aberrant social interactions and repetitive behaviors. WDR62 regulated dendritic spinogenesis and excitatory synaptic transmission in cortical pyramidal neurons. Finally, we revealed that retinoic acid gavages significantly alleviated ASD-like behaviors in mice with WDR62 haploinsufficiency, probably by complementing the expression of ASD and synapse-related genes. Our findings provide a new perspective on the relationship between the microcephaly gene WDR62 and ASD etiology that will benefit clinical diagnosis and intervention of ASD.
Mice ; Animals ; Microcephaly/genetics* ; Autistic Disorder/metabolism* ; Autism Spectrum Disorder/metabolism* ; Nerve Tissue Proteins/metabolism* ; Brain/metabolism* ; Mice, Knockout ; Cell Cycle Proteins/metabolism*

OBJECTIVE: To explore the genetic basis for a girl with distinctive facial features, epilepsy, intellectual disability, chronic constipation and hypopigmentation of neck and upper extremities. METHODS: Whole exome sequencing was carried out for the proband. Candidate variant was verified by Sanger sequencing. RESULTS: The proband was found to harbor a heterozygous nonsense c.586G>T (p.Glu196*) variant of the ZEB2 gene, which was unreported previously. The variant was not detected in either parent. CONCLUSION The ZEB2 gene c.586G>T (p.Glu196*) variant probably underlay the Mowat-Wilson syndrome in this patient. Hypopigmentation in the neck and upper extremities may be related to Mowat-Wilson syndrome. Prenatal diagnosis was recommended for subsequent pregnancies.
Facies ; Female ; Hirschsprung Disease ; Humans ; Hypopigmentation ; Intellectual Disability/genetics* ; Microcephaly ; Pregnancy ; Zinc Finger E-box Binding Homeobox 2/genetics*

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*

OBJECTIVE: To explore the genetic etiology of a child with microcephaly-cortical blind syndrome. METHODS: Clinical data of the child was collected. The child and her parents were subjected to whole exome sequencing (WES). Candidate variants were validated by Sanger sequencing. RESULTS: WES revealed that the child has harbored compound heterozygous variants c.1051C>T and c.609delA of the DIAPH1 gene. CONCLUSION The compound heterozygous variation c.1051C>T (p.R351X) and c.609delA (p.E203Efs*19) of the DIAPH1 gene probably underlay the microcephaly-cortical blindness syndrome in this child.
Blindness/genetics* ; Child ; Female ; Formins/genetics* ; Genetic Testing ; Humans ; Microcephaly/genetics* ; Mutation ; Pedigree ; Exome Sequencing

Dyskeratosis Congenita/genetics* ; Enterocolitis/genetics* ; Fetal Growth Retardation ; Humans ; Intellectual Disability/genetics* ; Microcephaly/genetics*

OBJECTIVE: To identify pathogenic variants in two patients with suspected for Mowat-Wilson syndrome (MWS). METHODS: Genomic DNA was extracted from peripheral blood samples of the patients and his family members, and gene variants were analysis by Trio-whole exome sequences and copy number variation sequencing. RESULTS: Patient 1 was found to carried a de novo heterozygous c.2769C>A (p.Y923*) nonsense variant of ZEB2 gene. The variant was not found in his healthy parents and sister. Patient 2 carried a de novo heterozygous frameshift variant of the ZEB2 gene, namely c.315delC (p.A105Afs*3), which has not been previously reported. Both variants were predicted to be pathogenic and can lead to premature occurrence of stop codons. CONCLUSION The heterozygous c.2769C>A (p.Y923*) and c.315delC (p.A105Afs*3) variants of the ZEB2 gene probably underlay the pathogenesis in the two patients. Gene testing has facilitated confirmation of the diagnosis and genetic counselling.
DNA Copy Number Variations ; Facies ; Hirschsprung Disease ; Humans ; Intellectual Disability/genetics* ; Microcephaly/genetics* ; Zinc Finger E-box Binding Homeobox 2/genetics*

OBJECTIVE: To detect potential mutation of the ASPM gene in a Chinese pedigree affected with autosomal recessive primary microcephaly 5 (MCPH5). METHODS: Peripheral venous blood samples were collected from the proband and her parents. Amniotic fluid sample was also collected upon her mother' s subsequent pregnancy. Following extraction of genomic DNA, PCR and Sanger sequencing were carried out to identify potential variants of the ASPM gene. RESULTS: The proband was found to harbor compound heterozygous variants of the ASPM gene, namely c.8214dupT (p.Q2739fs) in exon 18 and c.9541C>T (p.R3181X) in exon 23, which were respectively inherited from her father and mother. The fetus has found to have inherited the c.9541C>T (p.R3181X) variant only. CONCLUSION The c.8214dupT (p.Q2739fs) and c.9541C>T (p.R3181X) compound heterozygous variants of the ASPM gene probably underlay the pathogenesis of MCPH5 in this patient. Above finding has enabled genetic counseling and prenatal diagnosis for her family.
China ; Counseling ; Female ; Humans ; Microcephaly ; Mutation ; Nerve Tissue Proteins/genetics* ; Pedigree ; Pregnancy

OBJECTIVE: To explore the genetic basis for a child with ocular anomaly, microcephaly, growth retardation and intrauterine growth restriction. METHODS: The patient underwent ophthalmologic examinations including anterior segment photography, fundus color photography, and fundus fluorescein angiography. The patient and her parents were subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing and bioinformatic analysis. RESULTS: The patient was found to have bilateral persistent pupillary membrane and coloboma of inferior iris, in addition with macular dysplasia and radial pigmentation near the hemal arch of the temporal retina. She was found to have carried compound heterozygous missense variants of the PHGDH gene, namely c.196G>A and c.1177G>A, which were respectively inherited from her father and mother. Bioinformatic analysis suggested both variants to be pathogenic. CONCLUSION The patient was diagnosed with phosphoglycerate dehydrogenase deficiency. Above finding has enriched the phenotypic spectrum of the disease with ocular manifestations.
Carbohydrate Metabolism, Inborn Errors/genetics* ; Child ; Coloboma ; Female ; Humans ; Microcephaly/genetics* ; Mutation ; Phenotype ; Phosphoglycerate Dehydrogenase/genetics* ; Psychomotor Disorders/genetics* ; Seizures/genetics* ; Whole Exome Sequencing