• 대한소아치과학회지
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• 제35권4호
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• pp.713-717
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• 2008

백색증(albinism)이란 신체 내 melanin 합성의 부분적, 혹은 완전한 결핍에 의해 일어나는 질환이다. Melanin은 신체 내에서 머리카락, 눈, 피부 등에 분포하기 때문에 백색증 환자는 밝은 금발이나 갈색의 머리카락과 하얀 피부, 붉거나 갈색의 홍채를 갖는 특징적인 외모를 지닌다. 백색증 환자는 변이된 유전자 및 임상적 특징에 따라 크게 전신성 백색증, 안성 백색증, 부분적 백색증으로 나뉘며 그 밖에 많은 하위군이 존재하고 그에 따른 치료법이나 치과적 주의사항도 달라진다. 본 증례는 치아의 발육지연 여부 평가를 주소로 내원한 정신 지체가 동반된 전신성 백색증 환아로서 치아 발거 등의 관혈적 시술 및 보존수복, 공간 유지장치 등의 치료를 통해 양호한 결과를 보였기에 이를 보고하는 바이다.

• 한국동물위생학회지
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• 제29권4호
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• pp.489-492
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• 2006

Albinism, characterized by absence or lack of pigmentation from the hair, skin, hooves, nasal region and the eyes is rarely seen in cattle in Korea. A 15-day old calf, approximately weighing 28 kg has been conspicuously distinct from the rest of 40 herds of cattle raised in Sunchang country because of its white coat color, white muzzle and hooves and eyes with light pinkish iris. The calf was born of Korean indigenous cattle with no previously reported history of albinism since inception of the farm for over a decade period. It was assumed as a form of recessive genetic disorder. This observation was documented to present occurrence of albinism in cattle in Korea.

• 한국어류학회지
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• 제20권3호
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• pp.167-172
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• 2008

한국고유종이자 멸종위기종인 묵납자루, Acheilognathus signifer의 종보존을 위한 인공발생 및 사육이 진행되는 동안 눈과 피부 전반에 걸쳐 색소의 발현이 결핍된 oculocutaneous albinism 개체가 출현하였다. 정상과 알비노간의 형태적 차이 여부를 알아보기 위해 등 피부와 안구의 맥락막-망막 조직을 적출하여 조직학적 분석을 실시하였다. 그 결과 일반적인 형태는 서로 차이가 없었으나 멜라닌색소의 발현에서 현저한 차이를 보였다. 정상 묵납자루는 등 피부의 표피와 진피, 맥락막-망막색소상피층 및 홍채에 많은 수의 멜라닌세포와 흑색소포가 존재한 반면, 알비노의 등 피부에서는 색소가 거의 존재하지 않았고 맥락막-망막색소상피층과 홍채에서는 매우 제한된 분포를 보였다.

• 한국어류학회지
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• 제21권2호
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• pp.100-105
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• 2009

자원조성을 위한 방류용 메기 종묘를 생산하는 과정에서 출현한 전신성백색증 메기와 정상 메기의 눈, 부속지(수염, 등지느러미), 피부(등, 배, 체측)에 대한 조직학적 연구를 실시하였다. 외부형태적 차이는 발견되지 않았으나 체색에 있어서 정상 메기가 전체적으로 검은색을 띤 반면, 백색증 메기는 흰색 바탕에 노란색이 부분적으로 섞여 있었으며 눈은 붉은 색, 수염은 흰색을 보였다. 조사한 각 피부조직의 일반적인 형태는 정상 메기와 백색증 메기 간에 차이는 발견되지 않았다. 그러나 멜라닌 색소의 분포에 있어서 정상 메기의 경우, 망막의 색소상피층과 피부의 기저층에 길게 이어져 있던 색소세포층이 백색증 개체에서는 전혀 발견되지 않아 본 연구에서 확인된 백색증 메기는 $i^1/i^1$ 유형의 전신성백색증에 해당되었다.

• Journal of Yeungnam Medical Science
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• 제38권2호
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• pp.160-164
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• 2021

Oculocutaneous albinism (OCA) is a group of rare genetically heterogeneous disorders, characterized by hypopigmentation of the eyes, skin, and hair, which result in ocular abnormalities and a risk of developing skin cancer. Currently, there is no ophthalmologic procedure or drug that prevents the clinical features of OCA. Here, we report a new type of OCA in two, unrelated Korean families with the same OCA2 mutation. Affected individuals in this study are different from those of previous reports in two aspects: an inheritance pattern and clinical presentation. All reported patients with OCA have shown an autosomal recessive inheritance pattern, while our patients showed an autosomal dominant inheritance pattern. Small amounts of pigment can be acquired with age in OCA, but there is no substantial variation from adolescence to adulthood in this regard. A case where the patient attained normal pigmentation levels has never been reported. However, our patients displayed completely normal pigmentation in their late twenties. Whole exome sequencing and in-silico analysis revealed a novel mutation, OCA2 c.2338G>A p.(G780S) (NM_000275) with a high likelihood of pathogenicity. Sanger sequencing of p.G780S identified the same mutation in the affected individuals, which was not found in the family members with normal phenotype. We hypothesize that OCA2 G780S not only acts as a pathogenic variant of OCA but also induces pigmentation by enhancing the melanogenesis gene expression of other modifier genes, such as SLC45A2 and TPC2. These findings may provide further understanding of melanin biosynthesis and new treatment methods for OCA.

• 한국어류학회지
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• 제22권2호
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• pp.96-104
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• 2010

멸조위기종인 묵납자루 Acheilognathus signifer의 종복원을 위한 인공수정을 실시하는 과정에서눈과 피부의 색소발현이 결여된 백색증 개체가 출현하였다. 정상 묵납자루와 백색증 개체간 색소발현과 형태의 차이여부를 알아보기 위하여 몸통, 지느러미 눈 등 총 10개 부위에 대한 조직학적 검사를 실시하였다. 그 결과 정상 묵납자루의 경우, 멜라닌세포는 빛에 쉽게 노출되는 등부위와 상미병부, 맥락막-망막색소상피층 및 홍채에서 다량으로 분포하였다. 반면에 백색증 개체에서는 멜라닌세포가 등 부위와 등지느러미, 그리고 꼬리지느러미에서 아주 소량으로 분포하고 있었으며 눈의 맥락막-망막색소상피층 및 홍채에서는 색소결핍 현상이 뚜렷하게 관찰되었다.

• Pediatric Infection and Vaccine
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• 제31권1호
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• pp.122-129
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• 2024

Chediak-Higashi syndrome (CHS) is a rare haematological and immunodeficiency disorder that occurs in childhood leading to recurrent infections, bleeding tendencies and progressive neurological dysfunction. Partial oculocutaneous albinism occurs in almost all cases. The exact prevalence is unknown, and the disease is caused by over 70 identified mutations in the lysosomal trafficking regulator gene. The presence of a bright polychromatic appearance from hair shaft and abnormally large intracytoplasmic granules, especially within neutrophils and platelets in the bone marrow is highly suggestive. Treatment is largely supportive, and the only curative treatment is through an allogeneic hematopoietic stem cell transplant. Without transplant, most patients will enter an accelerated phase of hemophagocytic lymphohistiocytosis (HLH) which carries a high mortality rate. We present a young male with CHS who we had followed through and eventually developed a fulminant accelerated phase. We believe this is only the second reported case of CHS in Malaysia.

• Molecules and Cells
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• 제39권10호
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• pp.750-755
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• 2016

Although innate color preference of motile organisms may provide clues to behavioral biases, it has remained a longstanding question. In this study, we investigated innate color preference of zebrafish larvae. A cross maze with different color sleeves around each arm was used for the color preference test (R; red, G; green, B; blue, Y; yellow). The findings showed that 5 dpf zebrafish larvae preferred blue over other colors (B > R > G > Y). To study innate color recognition further, tyrosinase mutants were generated using CRISPR/Cas9 system. As a model for oculocutaneous albinism (OCA) and color vision impairment, tyrosinase mutants demonstrated diminished color sensation, indicated mainly by hypopigmentation of the retinal pigment epithelium (RPE). Due to its relative simplicity and ease, color preference screening using zebrafish larvae is suitable for high-throughput screening applications. This system may potentially be applied to the analysis of drug effects on larval behavior or the detection of sensory deficits in neurological disorder models, such as autism-related disorders, using mutant larvae generated by the CRISPR/Cas9 technique.

• Molecules and Cells
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• 제40권11호
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• pp.823-827
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• 2017

Genome editing using programmable nucleases such as CRISPR/Cas9 or Cpf1 has emerged as powerful tools for gene knock-out or knock-in in various organisms. While most genetic diseases are caused by point mutations, these genome-editing approaches are inefficient in inducing single-nucleotide substitutions. Recently, Cas9-linked cytidine deaminases, named base editors (BEs), have been shown to convert cytidine to uridine efficiently, leading to targeted single-base pair substitutions in human cells and organisms. Here, we first report on the generation of Xenopus laevis mutants with targeted single-base pair substitutions using this RNA-guided programmable deaminase. Injection of base editor 3 (BE3) ribonucleoprotein targeting the tyrosinase (tyr) gene in early embryos can induce site-specific base conversions with the rates of up to 20.5%, resulting in oculocutaneous albinism phenotypes without off-target mutations. We further test this base-editing system by targeting the tp53 gene with the result that the expected single-base pair substitutions are observed at the target site. Collectively, these data establish that the programmable deaminases are efficient tools for creating targeted point mutations for human disease modeling in Xenopus.