RUAN Miaohua,HU Sisi,ZHOU Xiaojun, et al. Children with MPPH I syndrome due to missense variant of PIK3R2 gene: A case analysis[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2022, 52(12): 999-1004.
Abstract:Objective: To summarize the clinical features and make a genetic analysis of a patient with megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome I (MPPH I). Methods: We retrospectively collected the clinical manifestations, imaging examinations and genetic analysis of a neonate with MPPH type I which was diagnosed at the Department of Neonatology of the First Affiliated Hospital of Wenzhou Medical University in January 2021. Literature was retrieved to summarize the clinical and genetic characteristic of MPPH type I casued by PIK3R2 variant. 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 missense c.1117G>A (p.Gly373Arg) variant of the PIK3R2 gene, which was unreported previously in China. The variant was not detected in either parent. The clinical characteristics of the 16 cases reported in the relevant literature review mainly presented a constellation of neurodevelopmental disorder, including megalencephaly, polymicrogyria,and hydrocephalus, and multiple neurological symptoms, including intellectual disability and epilepsy. PIK3R2 gene variants were identified, and most of them were p.Gly373Arg variant in exon 10 (fourteen cases), followed by p.Leu401Pro (one case), p.Asp557His (one case). Conclusion: The PIK3R2 gene c.1117G>A (p.Gly373Arg) variant may underlay the MPPH I syndrome in this patient. Hydrocephalus may be related to MPPH syndrome.Prenatal diagnosis is recommended for subsequent pregnancies.