5p13.2

1A1,AIM1,MATP,OCA4,SHEP5

Oculocutaneous albinism type IV (OCA IV)

OCA IV is an autosomal recessive disorder of melanin biosynthesis that results in congenital hypopigmentation of ocular and cutaneous tissues. Common developmental abnormalities of the eye like decreased visual acuity, macular hypoplasia, optic dysplasia, atypical choroidal vessels, and nystagmus are observed in patient suffering from OCA type IV. The severity of hypopigmentation is correlated with melanosome size, shape, melanin content and maturity of the melanosomal structures demonstrating that the encoded protein is a major determinant of mammalian pigmentation.

Melanoma

n 2017, Park et al reported that a few variants present in SLC45A2 gene can be a promising immune therapeutic target for melanoma with high tumor selectivity and reduced potential for autoimmune toxicity. It is associated with an increased risk for melanoma in light-skinned populations, and the encoded protein can elicit immune recognition. The Cancer Genome Atlas Research Network (TCGA) database reported that it is expressed by approximately 80% of cutaneous melanomas. In the same year Hafner et al showed that SLC45A2 (also called AIM1, absent in melanoma 1) function as a key suppressor of invasive phenotypes by working in association with the actin cytoskeleton. SLC45A2 becomes dysregulated and suppresses cytoskeletal remodelling in primary and metastatic prostate cancer and in non-malignant prostate epithelial cells. In 2012, Fernandez et al reported in a family that adult siblings presented with congenital neutropenia which later developed into Crohns Disease. Molecular characterisation revealed homozygous mutations both in G6PC3 and SLC45A2 in the sister and mutation in single allele for both genes in the brother.