[Analysis of a pedigree affected with HSAS syndrome due to a noval variant of L1CAM gene].

OBJECTIVE

To explore the genetic basis for a fetus with hydrocephalus.

METHODS

The fetus was found to have hydrocephalus upon ultrasonography duringthe second trimester. Following induced abortion, fetal tissue was collected for the extraction of DNA and whole exome sequencing.Sanger sequencing was used to verify the suspected variants in the family.

RESULTS

The fetus was found to harbor a hemizygous c.620A>G (p.Tyr207Cys) variant of the L1CAM gene (OMIM 308840),for which his mother and sister were heterozygous carriers. The same variant was not found in his father, uncle and grandparents.Based on the standards and guidelines of the American College of Medical Genetics and Genomics, the variant was predicted to be likely pathogenic (PM1+PM2+PP3+PP4).

CONCLUSION

The hemizygous c.620A>G (p.Tyr207Cys) variant of the L1CAM gene probably underlay the hydrocephalus in this fetus.