Prenatal diagnosis of skeletal dysplasia due to FGFR3 gene mutations: a 9-year experience : prenatal diagnosis in FGFR3 gene.

PURPOSE: Prenatal diagnosis with ultrasound findings compatible with skeletal dysplasia due to FGFR3 mutations over a 9 year period in pregnancies and abortuses.

METHODS

54 samples were studied. Aneuploidy studies were carried out on all samples. By sequencing analysis, we determined mutations for achondroplasia (ACH), hypochondroplasia (HCH), and type I and type II tanathophoric dysplasia (TD).

RESULTS

2 chorionic villi samples had a G380R mutation due to a mother with ACH; 4 amniotic fluid samples with TDs in which the foetuses had micromelia plus hypoplastic thoraces; 5 samples from abortuses with TDs. Neither ACH nor HCH occurred in sporadic cases.

CONCLUSIONS

Molecular studies in ongoing pregnancies are indicated in cases with an affected parent, a family history with positive molecular studies (maternal anxiety), and when the US finding demonstrates micromelia with a hypoplastic thorax. A protocol for tissues of abortuses should include an X-ray, pathologic anatomy, and genetic studies.