A Novel Deletion Mutation of the TYR Gene in a Patient With Oculocutaneous Albinism Type 1A

Background: Non syndromic oculocutaneous albinism type (OCA) is caused by mutations in tyrosinase (TYR), OCA2, TYRP1, MATP (SLC45A2), SLC24A5 and C10ORF11 genes. Screening for mutations is important in families with oculocutaneous albinism patients in order to accurately diagnose the albinism type, genetic counseling and future therapeutic purposes. Objectives: The Aim of this study was to investigate the founder effect of most frequent mutations in OCA patients. Methods: TYR gene was sequenced in 26 unrelated inbred OCA families as well as 56 unrelated healthy individuals. In addition, homozygosity mapping was performed using 13 STR markers for 6 OCA loci (TYR, OCA2, TYRP1, MATP (SLC45A2), SLC24A5 and C10ORF11 genes). Different mutations were found in these genes from which a single base duplication (c.286dupA) and two single base substitutions c.996G > A (p.M332I) and c.230G > A (p.R77Q) had the most frequencies among the OCA families. In order to investigate the founder effect of these mutations, the haplotypes of two STR markers (TYR-S1 and TYR-S2) inside the TYR gene were ascertained. Results: It was revealed that families with similar mutation harbored similar haplotype for the TYR STR markers too. Conclusions: We conclude that these mutations are possible founder mutations in the Iranian population.

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In-silico analysis of deleterious missense SNPs of human TYR gene associated with oculocutaneous albinism type 1 (OCA1)

Meta Gene ◽

10.1016/j.mgene.2020.100674 ◽

2020 ◽

Vol 24 ◽

pp. 100674 ◽

Cited By ~ 2

Author(s):

Malik Siddique Mahmood ◽

Saba Irshad ◽

Tehreem Aqdas Butt ◽

Hina Batool ◽

Sana Batool ◽

...

Keyword(s):

In Silico ◽

In Silico Analysis ◽

Oculocutaneous Albinism ◽

Tyr Gene ◽

Silico Analysis

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Mutational Analysis of TYR Gene Causing Oculocutaneous Albinism in Families from District Peshawar

International Journal of Human Genetics ◽

10.31901/24566330.2019/19.04.742 ◽

2019 ◽

Vol 19 (04) ◽

Author(s):

Farhan Ullah

Keyword(s):

Mutational Analysis ◽

Oculocutaneous Albinism ◽

Tyr Gene

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Two Novel Tyrosinase (TYR) Gene Mutations with Pathogenic Impact on Oculocutaneous Albinism Type 1 (OCA1)

PLoS ONE ◽

10.1371/journal.pone.0106656 ◽

2014 ◽

Vol 9 (9) ◽

pp. e106656 ◽

Cited By ~ 19

Author(s):

Vadieh Ghodsinejad Kalahroudi ◽

Behnam Kamalidehghan ◽

Ahoura Arasteh Kani ◽

Omid Aryani ◽

Mahdi Tondar ◽

...

Keyword(s):

Gene Mutations ◽

Oculocutaneous Albinism ◽

Tyr Gene

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Complex intragene deletion leads to oculocutaneous albinism in tanuki (Japanese raccoon dog)

Genome ◽

10.1139/gen-2020-0049 ◽

2020 ◽

Vol 63 (10) ◽

pp. 517-523

Author(s):

Yuji Mae ◽

Kenji Nagara ◽

Manabu Miyazaki ◽

Yukako Katsura ◽

Yuki Enomoto ◽

...

Keyword(s):

Oculocutaneous Albinism ◽

Nyctereutes Procyonoides ◽

Formation Processes ◽

Copper Binding ◽

Raccoon Dog ◽

Nucleotide Substitutions ◽

The Third ◽

Albino Phenotype ◽

Dna Scission ◽

Tyr Gene

Tanuki (Nyctereutes procyonoides viverrinus), or Japanese raccoon dog, is a canine native to Japan. Tanuki with complete oculocutaneous albinism are relatively frequent in mountainous areas of mainland Japan. Tyrosinase, which is encoded by the TYR gene, is an enzyme essential for the biosynthesis of melanin pigment. We examined the structure and nucleotide sequence of TYR in an albino tanuki and found that the third exon was removed due to a deletion of approximately 11 kb. In addition, two nonsynonymous nucleotide substitutions were found in the fifth exon. These mutations are possible causes of the albino phenotype; however, the order of occurrence is unclear. Even if the 11-kb deletion was not the first of these mutations, it is considered to cause a total loss of the tyrosinase function because the third exon carries codons for one of the two copper-binding sites of tyrosinase and these sites are essential for the enzyme function. Intriguingly, the deletion was not a simple removal of an 11-kb segment: an internal portion was retained as a segment in the reverse orientation. We propose possible formation processes for this mutation that involve multiple DNA scission events, or an inversion followed by a deletion.

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