OMIM ID:
Albinism, Oculocutaneous, Type VI
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
Nystagmus is usually present from birth and visual acuity is in the range of 20/100. There is marked hypopigmentation in the retina and the iris often transilluminates. OCT usually shows foveal flattening consistent with hypoplasia. Most patients experience severe photophobia and many have strabismus.
Systemic Features
There is usually complete loss or a severe reduction of melanin in skin, hair, and eyes. Hair color is blond but may become tinged with brown in older individuals. The skin may have pigmented nevi and has a tendency to tan in some patients.
Genetics
Inheritance
This is an autosomal recessive disorder resulting from mutations in SLC24A5 (15q21.1).
Pedigree
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.