Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2
The NM_005050.4(ABCD4):c.1346C>A(p.Thr449Lys) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T449M) has been classified as Uncertain significance.
ABCD4 (HGNC:68): (ATP binding cassette subfamily D member 4) The protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intra-cellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the ALD subfamily, which is involved in peroxisomal import of fatty acids and/or fatty acyl-CoAs in the organelle. All known peroxisomal ABC transporters are half transporters which require a partner half transporter molecule to form a functional homodimeric or heterodimeric transporter. The function of this peroxisomal membrane protein is unknown. However, it is speculated that it may function as a heterodimer for another peroxisomal ABC transporter and, therefore, may modify the adrenoleukodystrophy phenotype. It may also play a role in the process of peroxisome biogenesis. Alternative splicing results in several protein-coding and non-protein-coding variants. [provided by RefSeq, Jul 2017]
ABCD4 Gene-Disease associations (from GenCC):
methylmalonic acidemia with homocystinuria, type cblJ