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Query: UMLS:C0162671 (MELAS)
 587 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Old Order Amish populations in the US are one of the Plain People groups and are descendants of the Swiss Anabaptist immigrants who came to North America in the early eighteenth century. They live in numerous small endogamous demes that have resulted in reduced genetic diversity along with a high prevalence of specific genetic disorders, many of them autosomal recessive. Mitochondrial respiratory chain deficiencies arising from mitochondrial or nuclear DNA mutations have not previously been reported in the Plain populations. Here we present four different Amish families with mitochondrial respiratory chain disorders. Mutations in two mitochondrial encoded genes leading to mitochondrial respiratory chain disorder were identified in two patients. In the first case, MELAS syndrome caused by a mitochondrial DNA (mtDNA) mutation (m.3243A>G) was identified in an extended Amish pedigree following a presentation of metabolic strokes in the proband. Characterization of the extended family of the proband by a high resolution melting assay identified the same mutation in many previously undiagnosed family members with a wide range of clinical symptoms. A MELAS/Leigh syndrome phenotype caused by a mtDNA mutation [m.13513G>A; p.Asp393Asn] in the ND5 gene encoding the ND5 subunit of respiratory chain complex I was identified in a patient in a second family. Mutations in two nuclear encoded genes leading to mitochondrial respiratory chain disorder were also identified in two patients. One patient presented with Leigh syndrome and had a homozygous deletion in the NDUFAF2 gene, while the second patient had a homozygous mutation in the POLG gene, [c.1399G>A; p.Ala467Thr]. Our findings identify mitochondrial respiratory chain deficiency as a cause of disease in the Old Order Amish that must be considered in the context of otherwise unexplained systemic disease, especially if neuromuscular symptoms are present.
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PMID:Mitochondrial respiratory chain disorders in the Old Order Amish population. 2734 55

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome1 is one of the most frequently inherited mitochondrial disorders. MELAS syndrome is a systemic disease with multiple organ involvement.2 The most common mutation in MELAS is the m.3243A>G mutation in the MT-TL1 gene.2.
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PMID:Mitochondrial cytopathy with common MELAS mutation presenting as multiple system atrophy mimic. 2787 37

Melanocytes, the cells responsible for skin pigmentation, are present in other parts of the body, such as the ocular, auditory, nervous, and cardiac systems. Within these systems, their roles serve a different purpose than their classical counterparts in skin as pigment cells. Such roles include cell turnover in retinal pigment epithelium, maintenance of balance and prevention of environmental damage in the auditory neuroepithelium, role-playing as dendritic cells within the leptomeninges, and prevention of oxidative damage in adipose tissue. Vitiligo, commonly known as a skin pigmentation disorder, has also been associated with several systemic disorders, such as Vogt-Koyanagi-Harada disease and Alezzandrini, Kabuki, and MELAS syndromes. Therefore, since these conditions involve compromise of systems in which melanocytes reside, it is not surprising that vitiligo has other systemic associations. The authors present a detailed review of systemic associations of vitiligo and melanocytes' roles in other organ systems with a focus on systemic disease.
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PMID:Vitiligo: Not Simply a Skin Disease. 2852 6