Strabismus and nystagmus in oculocutaneous albinism: clinical perspectives, diagnosis, and role of neurotransmitters

Abstract

The rare recessive autosomal non-communicable disorder oculocutaneous albinism causes discoloration of the eye, hair, and skin. Oculocutaneous albinism is a hereditary group of disorders with sub-differential characteristics like reduction of pilar, cutaneous, and ocular pigmentation. Clinical characteristics and symptoms include strabismus, iris hypopigmentation, nystagmus, reduced visual acuity, foveal hypoplasia, refractive errors, photophobia, and colour-visual impairment. The associated genetic mutation results in the reduced activity of tyrosine activity required for the metabolism of melanin further. Genes that are majorly involved in different types of oculocutaneous albinism (OCA) are the TYR, MATP, SLC24A5, TYRP1, and SLCA5A2. Also, gene sequences LYST and HPS1 account for Chediak-Higashi syndrome and Hermansky-Pudlak syndrome, respectively, which have clinical symptoms of OCA. The exact gene mutation can be understood by various methods of a diagnostic approach, like denaturing high-performance liquid chromatography and sequential analysis that involves computational techniques. The most prevalent form of albinism, OCA1, is associated with a mutational defect in the TYR gene. Further, neuromodulators like GABA, acetylcholine, and dopamine are responsible for retinal abnormality and dysregulation, exacerbating the oculocutaneous albinism. Understanding all these genetic mutations and neurotransmitter deficiencies will help in generating the targeted gene and other drug delivery systems.