Updated Analysis of Albinism in Japan: 290 Families With Novel Pathological Variants

Area of Science:

• Genetics
• Ophthalmology
• Dermatology

Background:

• Albinism, a group of genetic disorders affecting pigmentation, includes oculocutaneous albinism (OCA) and ocular albinism (OA).
• Previous studies have characterized albinism subtypes in Japan, but a comprehensive, updated analysis is needed.

Purpose of the Study:

• To present an updated analysis of albinism in Japan, expanding previous research.
• To detail the frequency distribution of major and rare albinism subtypes.
• To identify novel pathological variants and expand the known variant spectrum in the Japanese population.

Main Methods:

• Analysis of 290 families with albinism, including 100 additional families since the previous study.
• Comprehensive genetic screening of additional families to identify albinism-causing variants.
• Review of patient data to determine subtype frequency and distribution.

Main Results:

• OCA4 remains the most prevalent subtype (23.1%), followed by OCA1 (19.7%), Hermansky-Pudlak syndrome (HPS) 1 (12.1%), and OCA2 (10.3%).
• Rare subtypes (OCA3, OCA6, HPS2-6) and OA were identified, demonstrating significant genetic diversity.
• Seventeen patients with previously unreported pathological variants were identified across multiple subtypes.

Conclusions:

• The genetic landscape of albinism in Japan is diverse, with established subtypes and rare forms.
• Identification of novel variants expands the albinism variant spectrum in Japan.
• Findings support the need for comprehensive clinical evaluation, genetic counseling, and multidisciplinary care for albinism patients.