Clinical and Genetic Characteristics of Young Children with Fragile X Syndrome

Purpose This study analyzed the clinical and genetic characteristics of young children with fragile X syndrome (FXS) and evaluated the significance of FXS genetic (FX) testing for children with global developmental delay (GDD). Methods FX testing was performed in 324 children aged <5 years and th...

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Main Authors: So-Hee Lee, Ji-Eun Jeong, Yoon-Young Jang, Jin-Kyung Kim
Format: Article
Language:English
Published: Korean Child Neurology Society 2021-07-01
Series:Annals of Child Neurology
Subjects:
Online Access:http://www.annchildneurol.org/upload/pdf/acn-2021-00353.pdf
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author So-Hee Lee
Ji-Eun Jeong
Yoon-Young Jang
Jin-Kyung Kim
author_facet So-Hee Lee
Ji-Eun Jeong
Yoon-Young Jang
Jin-Kyung Kim
author_sort So-Hee Lee
collection DOAJ
description Purpose This study analyzed the clinical and genetic characteristics of young children with fragile X syndrome (FXS) and evaluated the significance of FXS genetic (FX) testing for children with global developmental delay (GDD). Methods FX testing was performed in 324 children aged <5 years and their family members between 2007 and 2020. Fourteen children (10 boys, four girls) with abnormal results were finally included in this report. We retrospectively reviewed their medical records and categorized them based on genetic test results. The results of an analysis of the expanded cytosine-guanine-guanine trinucleotide (CGG) alleles of fragile X mental retardation 1 (FMR1) were divided into four groups: normal, intermediate (IM), premutation (PM), and full mutation (FM). Results Twelve of the 14 children presented with FM (nine boys, three girls), and one each with PM and IM, respectively. Five of the children with FM and the one with PM belonged to two families. At the initial visit, the mean age of the nine boys with FM was 24.8±9.7 months. They presented with significant GDD and markedly delayed language development. Most of them had subtle physical features. Two girls with FM presented with less severe developmental delay than the boys with FM, and they were identified via sibling studies. However, one girl presented with FM resulting from maternal uniparental disomy and severe developmental delay. Conclusion Even in the absence of a family history, physicians should consider FX testing for children with unexplained GDD. If there is a family history of FXS, FX screening tests should be performed for all family members.
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spelling doaj.art-8a47148b09654962a08afbe037333d052022-12-21T20:01:07ZengKorean Child Neurology SocietyAnnals of Child Neurology2635-909X2635-91032021-07-0129313413910.26815/acn.2021.003531234Clinical and Genetic Characteristics of Young Children with Fragile X SyndromeSo-Hee Lee0Ji-Eun Jeong1Yoon-Young Jang2Jin-Kyung Kim Department of Pediatrics, Daegu Catholic University School of Medicine, Daegu, Korea Department of Pediatrics, Daegu Catholic University School of Medicine, Daegu, Korea Department of Pediatrics, Daegu Catholic University School of Medicine, Daegu, KoreaPurpose This study analyzed the clinical and genetic characteristics of young children with fragile X syndrome (FXS) and evaluated the significance of FXS genetic (FX) testing for children with global developmental delay (GDD). Methods FX testing was performed in 324 children aged <5 years and their family members between 2007 and 2020. Fourteen children (10 boys, four girls) with abnormal results were finally included in this report. We retrospectively reviewed their medical records and categorized them based on genetic test results. The results of an analysis of the expanded cytosine-guanine-guanine trinucleotide (CGG) alleles of fragile X mental retardation 1 (FMR1) were divided into four groups: normal, intermediate (IM), premutation (PM), and full mutation (FM). Results Twelve of the 14 children presented with FM (nine boys, three girls), and one each with PM and IM, respectively. Five of the children with FM and the one with PM belonged to two families. At the initial visit, the mean age of the nine boys with FM was 24.8±9.7 months. They presented with significant GDD and markedly delayed language development. Most of them had subtle physical features. Two girls with FM presented with less severe developmental delay than the boys with FM, and they were identified via sibling studies. However, one girl presented with FM resulting from maternal uniparental disomy and severe developmental delay. Conclusion Even in the absence of a family history, physicians should consider FX testing for children with unexplained GDD. If there is a family history of FXS, FX screening tests should be performed for all family members.http://www.annchildneurol.org/upload/pdf/acn-2021-00353.pdffragile x syndromegenetic testingintellectual disability
spellingShingle So-Hee Lee
Ji-Eun Jeong
Yoon-Young Jang
Jin-Kyung Kim
Clinical and Genetic Characteristics of Young Children with Fragile X Syndrome
Annals of Child Neurology
fragile x syndrome
genetic testing
intellectual disability
title Clinical and Genetic Characteristics of Young Children with Fragile X Syndrome
title_full Clinical and Genetic Characteristics of Young Children with Fragile X Syndrome
title_fullStr Clinical and Genetic Characteristics of Young Children with Fragile X Syndrome
title_full_unstemmed Clinical and Genetic Characteristics of Young Children with Fragile X Syndrome
title_short Clinical and Genetic Characteristics of Young Children with Fragile X Syndrome
title_sort clinical and genetic characteristics of young children with fragile x syndrome
topic fragile x syndrome
genetic testing
intellectual disability
url http://www.annchildneurol.org/upload/pdf/acn-2021-00353.pdf
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