Meta-Biol

• Pathways

Retinoic acid (RA) is a biologically active analogue of vitamin A (retinol). RA plays an important role in regulating cell growth and differentiation. CYP26C1 is involved in the metabolic breakdown of RA by 4-hydroxylation. While CYP26C1 can hydroxylate the trans form, it is unique in hydroxylating the 9-cis isomer of RA (9cRA) (Taimi et al. 2004). Defects in CYP26C1 can cause focal facial dermal dysplasia 4 (FFDD4; MIM:614974), a rare syndrome characterised by facial lesions. Slavotinek et al. identified compound heterozygosity for a 7-bp tandem duplication (844_851dupCCATGCA) in exon 4 of the CYP26C1 gene, causing a frameshift mutation, Q477Hfs*129, and a 1433A-G transition in exon 6 that results in an R478R missense mutation. Both mutations caused loss of CYP26C1 function when transfected into COS-1 cells (Slavotinek et al. 2013).