Dataset Information

Fragile X Syndrome Caused by Maternal Somatic Mosaicism of FMR1 Gene: Case Report and Literature Review.

ABSTRACT: Fragile X syndrome (FXS) is caused by an abnormal expansion of the number of trinucleotide CGG repeats located in the 5' UTR in the first exon of the FMR1 gene. Size and methylation mosaicisms are commonly observed in FXS patients. Both types of mosaicisms might be associated with less severe phenotypes depending on the number of cells expressing FMRP. Although this dynamic mutation is the main underlying cause of FXS, other mechanisms, including point mutations or deletions, can lead to FXS. Several reports have demonstrated that de novo deletions including the entire or a portion of the FMR1 gene end up with the absence of FMRP and, thus, can lead to the typical clinical features of FXS. However, very little is known about the clinical manifestations associated with FMR1 gene deletions in mosaicism. Here, we report an FXS case caused by an entire hemizygous deletion of the FMR1 gene caused by maternal mosaicism. This manuscript reports this case and a literature review of the clinical manifestations presented by carriers of FMR1 gene deletions in mosaicism.

SUBMITTER: Gomez-Rodriguez MJ

PROVIDER: S-EPMC9498456 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Fragile X Syndrome Caused by Maternal Somatic Mosaicism of <i>FMR1</i> Gene: Case Report and Literature Review.

Gómez-Rodríguez Maria Jose MJ Morales-Conejo Montserrat M Arteche-López Ana A Sánchez-Calvín Maria Teresa MT Quesada-Espinosa Juan Francisco JF Gómez-Manjón Irene I Palma-Milla Carmen C Lezana-Rosales Jose Miguel JM Pérez de la Fuente Ruben R Martin-Ramos Maria-Luisa ML Fernández-Guijarro Manuela M Moreno-García Marta M Alvarez-Mora Maria Isabel MI

Genes 20220908 9

Fragile X syndrome (FXS) is caused by an abnormal expansion of the number of trinucleotide CGG repeats located in the 5' UTR in the first exon of the <i>FMR1</i> gene. Size and methylation mosaicisms are commonly observed in FXS patients. Both types of mosaicisms might be associated with less severe phenotypes depending on the number of cells expressing FMRP. Although this dynamic mutation is the main underlying cause of FXS, other mechanisms, including point mutations or deletions, can lead to ...[more]

PMID: 36140775

Similar Datasets

Project description:ObjectiveNoonan syndrome (NS), an autosomal dominant disease known as a RASopathy, is caused by germline mutations in mitogen-activated protein kinase pathway genes. A RIT1 gene mutation has been found to cause NS. The present study summarizes RIT1 gene mutation sites and associated clinical phenotypes.MethodsWe retrospectively analyzed the clinical characteristics of a case of NS caused by RIT1 mutation in our hospital, and searched the PubMed database, China National Knowledge Infrastructure (CNKI) database and Wanfang database with the keywords Noonan syndrome and RIT1. Studies published between May 1, 2014 and July 1, 2021 were retrieved. By reviewing the abstracts and full text of the studies, we screened NS cases associated with RIT1 mutation in children 0-18 years of age. The clinical characteristics of these cases were summarized.ResultsA total of 41 cases were analyzed, including 13 boys and 28 girls. There were 14 premature cases. The age at diagnosis was 4 days to 18 years, and 10 cases were diagnosed at 0-1 years of age. Common amino acid substitution positions included 57 (13/41), 95 (7/41), 82 (8/41), and 90 (4/41). A total of 63.63% cases had abnormal prenatal examination results, manifesting mainly as fetal neck edema, polyhydramnios and cardiac malformation. With respect to abnormal conditions after birth, 70-80% of patients had typical developmental malformations of the face, neck and thorax; 19/35 patients had abnormal lymphatic development; and a portion of patients had short stature and motor development disorders. A total of 87.80% (36/41) patients had cardiac dysplasia, among which hypertrophic cardiomyopathy (HCM) accounted for 58.53%. A total of 84.62% of patients carrying the p.A57G mutation had HCM, but no HCM was found in patients with the p.G95A mutation. A total of 34.15% of patients had pulmonary artery or pulmonary valve stenosis (PVS). In patients with the p.M90I mutation, 75% had PVS. Patients with concurrent HCM and PVS accounted for 19.51 and 48.78% of patients had supraventricular tachycardia.ConclusionA RIT1 gene mutation causing NS was associated with a high rate of abnormal prenatal examination findings. Most patients had typical NS craniofacial deformities, and some have short stature and motor development disorders. The cardiac deformity rate was high, and HCM was common. Some patients had supraventricular arrhythmias. Heart abnormalities showed high heterogeneity, given the various mutation loci.

Dataset Information

Fragile X Syndrome Caused by Maternal Somatic Mosaicism of FMR1 Gene: Case Report and Literature Review.

Publications

Fragile X Syndrome Caused by Maternal Somatic Mosaicism of <i>FMR1</i> Gene: Case Report and Literature Review.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets