9 Feb 2018 Abstracts

Investigating the HEXA Gene for Mutations to Confirm the Presence of Late Onset Tay-Sachs

Josh Slostad '18

Tay-Sachs is a disease that causes rapid developmental stagnation and death in infants. It primarily affects people of French Canadian, Cajun, and Ashkenazi Jewish descent. In recent years an alternate form of the disease, called late onset Tay-Sachs (LOTS), has been described. LOTS is caused by the inheritance of one null allele and a pseudodeficiency allele of the hexosaminidase A (HEXA) gene. The mutation rate of the pseudodeficiency is not well known. The aim of this experiment was to examine the DNA of the descendants of an Ashkenazi Jewish individual who was believed to have undiagnosed LOTS.The purpose of this case study is to attempt to confirm this suspected diagnosis by identifying potential mutations in the family members. DNA of the HEXA gene from three family members of the suspected LOTS patient (wife and 2 daughters) and one control set (unrelated female) was sequenced. The sequences were aligned and compared both by hand and using the NCBI Blast database and the Benchling tool. No known mutations or confirmed novel mutations have been found in all fourteen exons sequenced. Currently re-sequencing of some regions that showed potential single nucleotide polymorphisms (SNPs) as well as sequencing the promoter region of the gene is underway. If a mutation is confirmed this research could help pave the way for further genetic testing in the broader population in order to fully grasp the prevalence of LOTS pseudodeficiency alleles within the Ashkenazi population.