[Mutations and polymorphisms of the P gene associated with oculocutaneous albinism type II].
Oculocutaneous albinism typeII(OCA2), the most common type of albinism, is an autosomal recessive disorder. It is caused by mutations in the P gene, which is located on chromosome 15q11.1-q12 and divided into 24 exons and 23 introns. P gene codes for 838-amino-acid integral membrane protein with 12 putative transmembrane domains, but the exact function is not clear yet. There are at least 60 pathologic mutations and 43 non-pathologic polymorphisms have been found. Pathologic mutations include missense mutations, nonsense mutations, frameshift mutations and splice-sit mutations. But unlike TYR gene, most of P gene mutations are located on the C-terminal and don' t cluster in defined regions. It is difficult to define the pathologic mutations since many non-pathologic polymorphisms also lie in exons. Some non-pathologic missense mutations may be associated with phenotypic variation in normally pigmented individuals and need to further study.
Duan
Hong-Lei
HL
Department of Medical Genetics, Zhongshan Medical College, SunYat-sen University, Guangzhou 510089, China. hongleihotmail@hotmail.com
Zheng
Hui
H
Li
Hong-Yi
HY
D016115:Albinism, Oculocutaneous / Q000145:classification / Q000235:genetics*; D002884:Chromosomes, Human, Pair 15; D006801:Humans; D026901:Membrane Transport Proteins / Q000235:genetics*; D009154:Mutation; D011110:Polymorphism, Genetic
D026901:Membrane Transport Proteins; C489600:OCA2 protein, human