Open AccessGenetic analyses of Vietnamese patients with oculocutaneous albinism
Author(s) -
Thuong Ma Thi Huyen,
Anh Luong Thi Lan,
Nhung Vu Phuong,
Ngoc Tran Thi Bich,
Lan Hoang Thu,
Phuong Doan Kim,
Ha Nguyen Hai,
Hai g,
Ton Nguyen Dang
Publication year - 2022
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/jcla.24625
Subject(s) - oculocutaneous albinism , hypopigmentation , albinism , genetics , consanguinity , genetic counseling , missense mutation , sanger sequencing , medicine , mutation , compound heterozygosity , exome sequencing , dermatology , biology , gene
Background Oculocutaneous albinism (OCA) is an autosomal recessive disease with hypopigmentation in skin, hair, and eyes, causing by the complete absence or reduction of melanin in melanocytes. Many types of OCA were observed based on the mutation in different causing genes relating to albinism. OCA can occur in non‐syndromic and syndromic forms, where syndromic OCA coexists with additional systemic consequences beyond hypopigmentation and visual‐associated symptoms. Methods We performed whole exome sequencing in seven affected individuals (P1‐P7) for mutation identification, and then, Sanger sequencing was used for verifications. Results Among them, five patients (P1‐P5) have mutations on TYR gene including c.346C > T, c.929insC, c.115 T > C, and c.559_560ins25. The mutation on OCA2 and HPS1 genes was found in patient 6 (P6, OCA2 c.2323G > A) and patient 7 (P7, HPS1 c.972delC), respectively. Confirmation in parents (except the family of the elderly patient, P5) showed that the mother and the father in each family carried one of the variants that were detected in patients. Additionally, the effective genetic counseling was applied in the third pregnancy of a family with two OCA children (P1 and P2). Conclusion To our best knowledge, this is the first case with a novel homozygous missense mutation (c.115 T > C, p.W39R) in the TYR gene. This study provides a broader spectrum of mutations linked to the oculocutaneous albinism, an additional scientific basis for diagnosis, and appropriate genetic counseling for risk couples.