Hyper IgM Syndrome Type 1 (HIGM-1) is the X-linked variant of the hyper IgM syndrome.peripheral: Purine nucleoside phosphorylase deficiency Hyper IgM Syndrome Type 1 (HIGM-1) is the X-linked variant of the hyper IgM syndrome. The affected individuals are virtually always male, because males only have one X chromosome, received from their mothers. Their mothers are not symptomatic, even though they are carriers of the allele, because the trait is recessive. Male offspring of these women have a 50% chance of inheriting their mother's mutant allele.