Clinical features and FGFR3 mutations of children with achondroplasia / 中国当代儿科杂志

OBJECTIVES@#To study the clinical features and fibroblast growth factor receptor 3 (FGFR3) gene mutations of children with achondroplasia (ACH) through an analysis of 17 cases.@*METHODS@#A retrospective analysis was performed on the clinical data and FGFR3 gene detection results of 17 children with ACH who were diagnosed from January 2009 to October 2021.@*RESULTS@#Of the 17 children with ACH, common clinical manifestations included disproportionate short stature (100%, 17/17), macrocephaly (100%, 17/17), trident hand (82%, 14/17), and genu varum (88%, 15/17). The common imaging findings were rhizomelic shortening of the long bones (100%, 17/17) and narrowing of the lumbar intervertebral space (88%, 15/17). Major complications included skeletal dysplasia (100%, 17/17), middle ear dysfunction (82%, 14/17), motor/language developmental delay (88%, 15/17), chronic pain (59%, 10/17), sleep apnea (53%, 9/17), obesity (41%, 7/17), foramen magnum stenosis (35%, 6/17), and hydrocephalus (24%, 4/17). All 17 children (100%) had FGFR3 mutations, among whom 13 had c.1138G>A hotspot mutations of the FGFR3 gene, 2 had c.1138G>C mutations of the FGFR3 gene, and 2 had unreported mutations, with c.1252C>T mutations of the FGFR3 gene in one child and c.445+2_445+5delTAGG mutations of the FGFR3 gene in the other child.@*CONCLUSIONS@#This study identifies the unreported mutation sites of the FGFR3 gene, which extends the gene mutation spectrum of ACH. ACH is a progressive disease requiring lifelong management through multidisciplinary collaboration.

Antenatal diagnosis of Thanatophoric dysplasia: a case report and review of literature.

Thanatophoric dysplasia is the lethal skeletal dysplasia characterized by marked underdevelopment of the skeleton and short-limb dwarfism. Foetus has short neck, narrow thoracic cage and protruberant abdomen. Other anatomical features include a relatively enlarged head with frontal bossing, platyspondyly, telephone handle femurs. Thanatophoric dysplasia is usually diagnosed using second trimester ultrasonography. We report this rare entity from rural India with emphasis on its anatomical features along with review of relevant literature.

Thanatophoric dysplasia in a dichorionic twin confirmed by genetic analysis at the early second trimester: A case report and literature review

Thanatophoric dysplasia (TD) is caused by mutation of the gene that encodes fibroblast growth factor 3 (FGFR3). Owing to the poor prognosis for TD, prenatal diagnosis is critical to optimal perinatal management. We report here a case of TD in twin pregnancy, which was prenatally diagnosed by DNA analysis following amniocentesis at 15 weeks, and was managed by selective fetal termination. Prenatal ultrasonography and molecular analysis to detect TD-specific mutations enable accurate diagnosis of FGFR3-related TD in utero and appropriate obstetrical management at early gestation during twin pregnancy.

FGFR3 gene mutation analysis of achondroplasia and hypochondroplasia families / 临床儿科杂志

Objective To screen the sequence of fibroblast growth factor receptor 3 (FGFR3) genes in children with dys-chondroplasia and their family members for searching the mutations. Methods The sequence of exon 10 and exon 13 in muta-tion hot spot region of FGFR3 gene in seven families was analyzed using polymerase chain reaction (PCR) and DNA sequenc-ing technology. Results The c.1138G>A missense mutation in exon 10 was found in 4 probands who were diagnosed as achon-droplasia (ACH), while this mutation was absent in their parents. The c.1620C>A missense mutation in exon 13 was found in one girl and her mother who both were diagnosed as hypochondroplasia (HCH) with mild symptoms. Neither mutation men-tioned above was found in the other two probands. Conclusions Through detecting the mutation in exon 10, exon 13 of FGFR3 gene, most patients of ACH or HCH can be finally diagnosed. However, it is necessary to perform the mutation screening on the other zones of FGFR3 gene and on other related genes for a few cases.

Clinical Experiences of Molecular Genetic Evaluation of Achondroplasia in Prenatal and Neonatal Cases

PURPOSE: The purpose of this study was to assess the characteristics of achondroplasia (ACH) diagnosed in fetuses or neonates and to evaluate the usefulness of a molecular genetic testing to confirm ACH. MATERIALS AND METHODS: The medical and ultrasonographic records of 16 pregnant women, who had molecular genetic testing for ACH performed on their fetus or neonate at the Cheil General Hospital between February 1999 and April 2013, were retrospectively analyzed. Detection of G1138A and G1138C mutations of the fibroblast growth factor receptor 3 (FGFR3) gene was accomplished by polymerase chain reaction - restriction fragment length polymorphism analysis. RESULTS: Of the eight fetuses and two neonates who were suspected of having ACH during pregnancy, four fetuses and one neonate was confirmed to have ACH and they all carried the heterozygous G1138A mutation. Out of 6 cases which had a history of ACH in prior pregnancies, three had genetic information for the previous fetuses while the other three did not. All six fetuses had no mutations at G380R. However, the one fetus of pregnant woman with non-confirmed ACH showed shortened long bone on ultrasound thereafter and the fetus was identified as having oto-spondylo-megaepiphyseal dysplasia after birth. CONCLUSION: Korean patients with achondroplasia have the heterozygous G1138A mutation that is most commonly defined in other countries. Molecular genetic evaluations of ACH are helpful not only for establishing diagnosis but for appropriate counseling with subsequent pregnancies.