Xi Hui, Zhang Yanan, Qin Liyan, Kang Huaixing, Duan Ranhui, Jia Zhengjun, Wang Hua
Center of Hunan Provincial Prenatal Diagnosis, Hunan Maternal and Child Health Hospital, Changsha, Hunan 410008, China.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2018 Oct 10;35(5):653-656. doi: 10.3760/cma.j.issn.1003-9406.2018.05.007.
To assess the value of genetic testing for Fragile X syndrome (FXS).
A domestically made diagnostic kit based Tri-primer-PCR method was used to detect mutations of the FMR1 gene among 6 pedigrees with unexplained intellectual disability. The results were verified by methylation PCR and Southern blotting.
Pedigrees 1 and 6 were positive for the screening. In pedigree 1, a full-mutation allele with methylation was identified in the proband and his mother, which was passed on to the fetus. In pedigree 6, the proband was mosaic for a full-mutation allele and a pre-mutation allele. His sister was asymptomatic with a full-mutation. His mother carried pre-mutation allele, while his father and sister's baby were normal. The number of CGG repeats of the pedigrees 2 to 5 were in the normal range.
Genetic testing can provide an effective way to prevent FXS caused by FMR1 mutations and enable prenatal diagnosis for families with a high risk for the disease.
