Abstract:

Objective: Prenatal diagnosis and genetic counseling of a Lesch-Nyhan syndrome family were performed by the studies of point mutation in the HPRT1 gene. Methods: The older child born by the patient was the Lesch-Nyhan Syndrome (proband),who was caused by the hemizygotic variation of HPRT1 gene (NM_000194) c.289_290delGT (p.V97Rfs *10). The second-born died, whose symptoms were similar to the older child, and HPRT1 gene test was not performed. Without pre-pregnancy genetic counseling before the third natural pregnancy, the method of polymerase chain reaction combined with Sanger sequencing was used to study the point mutation of HPRT1 gene in the family under the principle of informed consent, and genetic counseling was provided. Results: The hemizygotic variation c.289_290delGT(p.V97Rfs*10) of the HPRT1 gene (NM_000194) was detected in the proband. The heterozygous variation c.289_290delGT(p.V97Rfs*10) of the HPRT1 gene (NM_000194) was detected in the mother. The variation c.289_290delGT (p.V97Rfs*10) of the HPRT1 gene (NM_000194) was not detected in the fetus. The proband′s mother was advised to continue pregnancy, and finally gave birth to a healthy baby girl with normal physical examination at 1 year old. Conclusions: The mutation locus of HPRT1 gene of proband is inherited from the mother. Clinical attention should be paid to gene testing and prenatal diagnosis of other members of the proband′s lineage, and perfect genetic counseling should be given to avoid the birth of children with the Lesch-Nyhan syndrome and other rare genetic diseases.

Key words: Lesch-Nyhan syndrome, Hypoxanthine phosphoribosyltransferase, Genetic variation, Prenatal diagnosis, Genetic counseling, Hyperuricemia, Developmental disabilities