Genotypic spectrum of albinism in Mali

Area of Science:

• Genetics
• Ophthalmology
• Human Biology

Background:

• Albinism is a genetic disorder causing hypopigmentation and vision impairment.
• Genotypic studies are common globally, but data from sub-Saharan Western Africa is scarce.
• Understanding regional genetic variations is crucial for diagnosis and management.

Purpose of the Study:

• To determine the genotypic spectrum of albinism in patients from Mali.
• To identify novel albinism-associated genetic variants in this population.
• To compare findings with albinism genotypic data from other African regions.

Main Methods:

• Genetic analysis of all known albinism genes in 23 Malian patients.
• Variant identification and characterization.
• Comparison of identified variants with existing global and African databases.

Main Results:

• Oculocutaneous albinism type 2 (OCA2) was the most frequent form (17/23 patients).
• A specific OCA2 variant (NM_000275.3:c.819_822delinsGGTC) was highly prevalent.
• Four novel variants (two in TYR, two in OCA2) were discovered, including a deep intronic variant affecting OCA2 splicing.
• The common OCA2 exon 7 deletion found elsewhere in Africa was absent in this cohort.
• OCA1 and OCA4, rare in other African studies, were present in this Malian group.

Conclusions:

• This study provides the first genotypic spectrum of albinism in Western sub-Saharan Africa.
• The genetic profile of albinism in Mali shows distinct features compared to Eastern and Southern Africa.
• Further research is needed to understand the implications of these findings for albinism care in the region.