Genetic Evaluation of the Parents Following Demise of the Index Case: Report of a Family with Fucosidosis.

It is common in obstetric practice to encounter couples who seek prenatal genetic counseling and testing in view of history of known or suspected genetic disorders in the previous offspring or in other family members. Recent advances in genetic testing techniques, especially the availability of the next-generation sequencing (NGS) technology, have greatly facilitated genetic evaluation of the proband and/or the consultand couple and enabled provision of accurate genetic counseling and prenatal genetic testing in such clinical scenarios. However, even in this era of NGS, comprehensive clinical history taking and detailed phenotype characterization through clinical examination and thorough perusal of available medical records, are very important and essential for accurate diagnosis, as reiterated by this report of a 30-year-old third gravida, who was referred for prenatal genetic counseling and testing, in view of history of death of the first offspring due to a suspected neurogenetic disorder. Retrospective clinical diagnosis for the deceased index child with the help of available medical records and reports, followed by relevant NGS-based clinical exome sequencing of the couple, helped to arrive at a definitive diagnosis of fucosidosis, based on which accurate prenatal genetic testing could be done.