Clinical Phenotype of an Italian Case of Oculocutaneous Albinism Type 4 Caused by Novel Mutations in the Matp Gene

Abstract

Purpose: : To describe the ocular findings of an Italian patient with new mutation in MATP gene.

Methods: : A 4 years old male with oculocutaneous albinism underwent ophthalmologic examination including best-corrected visual acuity by Snellen visual charts, slit-lamp biomicroscopy, dilated fundus examination, fundus photography, scanning laser ophthalmoscopy, optical coherence tomography, electroretinogram. The genetic testing was performed by direct sequencing analysis of the MATP gene. To validate missense variations 100 control chromosomes were analyzed by high performance liquid chromatography (dHPLC).

Results: : The clinical phenotype of patient showed some pigmentation that is, the hair was pale blond and the irides were grey-blu. He presented nystagmus with a best corrected visual acuity of 20/200 in right eye and 20/100 in left eye. The fundus appearance showed indistinct pigmentation of the pigmented epithelia of the retina. OCT analysis demonstrated macula hypoplasia with a foveal thickness of 228 µm in right eye and 216 µm in left eye. There was diffuse fundus autofluorescence with local hypofluorescence at the fovea. Molecular investigation revealed that the patient is a compound heterozygous harboring two novel missense substitutions, p.V126D (c.T375A) and p.G370R (c.G1108), affecting the first and fifth exons of the MATP gene.

Conclusions: : This is the first report of an Italian patient with OCA caused by novel mutations in the MATP gene. The clinical phenotype associated is characterized by a minimal foveal pit and some macular and skin pigmentation.

Keywords: genetics • nystagmus • retinal degenerations: hereditary