Homozygous 896delT (c.764del) in Somali-American Siblings With Cystic Fibrosis.

Cystic fibrosis is an autosomal recessive condition historically reported to be predominantly in those of European ancestry; however, more cases of CF are reported in those with non-European ancestry as we improve diagnostic awareness and aptitude. We report two cases of Somali siblings with rare CFTR 896delT (c.764del; p.Ile255ThrfsX6; dbSNP rs2485020167; ClinVar ID 2682475; NM_000492.4:c.764del) homozygous variants who manifested classic CF lung and hepatic disease. They presented with elevated immunoreactive trypsinogen on newborn screen but required exon sequencing to confirm their rare variant. This type of variant causes a frameshift that leads to an early stop codon; therefore, there is currently no available disease-modulating therapy. Our cases highlight the clinical phenotype of this variant and increase awareness of the importance of inclusivity in our current CF screening methods.