label: Immunoglobulin Superfamily Member 1 Deficiency Syndrome
label_lc: immunoglobulin superfamily member 1 deficiency syndrome
description: "An X-linked recessive syndrome caused by loss-of-function mutation(s) in IGSF1, encoding immunoglobulin superfamily member 1. This condition can result in central hypothyroidism, macroorchidism, delayed puberty, and variable prolactin deficiency."