MCAHSS-3 is inherited in an autosomal recessive manner. Homozygous missense and splice site variants in PIGT were described. MCAHSS-3 is a GPI-anchor synthesis disorder. Notable reduction in cell surface presentation of GPI-anchored proteins was reported among probands with homozygous splice site variants in PIGT.
A different condition (not studied here) caused by mutations in PIGT is acquired Paroxysmal Nocturnal Hemoglobinuria (PNH). In a patient with a heterozygous germline splice site mutation in PIGT and, a somatic 8-MB deletion in granulocytes affecting the other copy of PIGT was identified which caused PNH type 2 . This is similar to PNH type 1 caused by somatic PIGA mutations.
PIGT