Genetic analyses of oculocutaneous albinism types 1 and 2 with four novel mutations.

Abstract

BACKGROUND:

Oculocutaneous albinism (OCA) is a human autosomal-recessive hypopigmentation disorder with hypopigmentation in the skin, hair, and eyes. OCA1 and OCA2 are caused by mutations of the TYR and OCA2 genes, respectively, which are responsible for most oculocutaneous albinism. However, the incidence of oculocutaneous albinism patients in Guangxi remains unclear.

METHODS:

To evaluate the molecular basis of oculocutaneous albinism in thirty-six patients in Guangxi, China. Peripheral venous blood samples were collected from these unrelated patients. The TYR and OCA2 genes of all individuals were analyzed by direct DNA sequencing and the sequences compared with are reference database and bioinformatics analysis.

RESULTS:

Among the 36 OCA patients, 8(22.2%) were found mutations on TYR gene, 28 (77.8%) on OCA2. And we identified Twenty-seven different TYR and OCA2 mutations in these patients, including one novel TYR framshift mutation c.561_562insTTATTATGTGTCAAATTATCCCCCA, three novel OCA2 mutations: one nonsense mutation c.2195C > G(p.S732X), one deletation mutation(c.1139-1141delTGG), one missense mutations c.2495A > C(p.H832P). The population screening and the bioinformatic analysis to determined the effects of the mutations, which revealed these four novel mutations were pathogenic.

CONCLUSIONS:

This study expands the mutation spectrum of oculocutaneous albinism. Four novel mutational alleles c.1139-1141delTGG, c.1832 T > C and c.2195C > G and of the OCA2 gene and c.561_562insTTATTATGTGTCAAATTATCCCCCA of TYR were associated with OCA. The genotype-phenotype correlations suggest that molecular diagnosis is more accurate and important in OCA.

• Authors: Qi Yang, Sheng Yi, Mengting Li, Bobo Xie, Jinsi Luo, Jin Wang, Xiuliang Rong, Qinle Zhang, Zailong Qin, Limei Hang, Shihan Feng, Xin Fan
• Journal: BMC medical genetics (BMC Med Genet) Vol. 20 Issue 1 Pg. 106 (06 13 2019) ISSN: 1471-2350 [Electronic] England
• PMID: 31196117 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Membrane Transport Proteins
• OCA2 protein, human
• Monophenol Monooxygenase

Topics

• Adolescent
• Adult
• Albinism, Oculocutaneous (diagnosis, ethnology, genetics)
• Asian People (genetics)
• Base Sequence
• Child
• Child, Preschool
• China
• DNA Mutational Analysis (methods)
• Female
• Genetic Association Studies
• Genetic Predisposition to Disease (ethnology, genetics)
• Humans
• Infant
• Infant, Newborn
• Male
• Membrane Transport Proteins (genetics)
• Monophenol Monooxygenase (genetics)
• Mutation