<unk>  can be suspected based on clinical findings, however confirmation of the diagnosis requires the identification of biallelic pathogenic variants in<unk>  through genetic testing. Traditional screening tests utilized for congenital disorders of glycosylation, including carbohydrate deficient transferrin are not diagnostic in<unk> . To date all variants identified as being causative of<unk>  have been sequence variants, rather than copy number variants. This spectrum may change as additional cases are identified. A common nonsense variant (c.1201A>T (p.Arg401Ter)) accounts for approximately a third of pathogenic variants identified, and is associated with a more severe clinical course. There is also a biomarker for<unk> . When the<unk>  protein is missing or not functioning correctly, a specific molecule called GlcNAc-Asn (GNA) accumulates. GNA is elevated in individuals with<unk>  compared to individuals without the disease. Elevated GNA alone is not enough to confirm an<unk>  diagnosis, but in combination with molecular genetic testing and clinical findings, it can provides additional support for<unk> .
NGLY1 deficiency
LRBA deficiency
WNT4 deficiency
PMM2 deficiency
Janus kinase 3 deficiency
ZC4H2 deficiency
CDKL5 deficiency disorder
DOCK8 deficiency