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Autosomal Recessive Condition (autosomal + recessive_condition)

Distribution by Scientific Domains

Medical Sciences	50%
Life Sciences	50%

Selected Abstracts

The adenine nucleotide translocase type 1 (ANT1): A new factor in mitochondrial disease

IUBMB LIFE, Issue 9 2005
J. Daniel Sharer
Abstract Mitochondrial disorders of oxidative phosphorylation (OXPHOS) comprise a growing list of potentially lethal diseases caused by mutations in either mitochondrial (mtDNA) or nuclear DNA (nDNA). Two such conditions, autosomal dominant progressive external ophthalmoplegia (adPEO) and Senger's Syndrome, are associated with dysfunction of the heart and muscle-specific isoform of the adenine nucleotide translocase (ANT1), a nDNA gene product that facilitates transport of ATP and ADP across the inner mitochondrial membrane. AdPEO is a mtDNA deletion disorder broadly characterized by pathology involving the eyes, skeletal muscle, and central nervous system. In addition to ANT1, mutations in at least two other nuclear genes, twinkle and POLG, have been shown to cause mtDNA destabilization associated with adPEO. Senger's syndrome is an autosomal recessive condition characterized by congenital heart defects, abnormalities of skeletal muscle mitochondria, cataracts, and elevated circulatory levels of lactic acid. This syndrome is associated with severe depletion of ANT1, which may be the result of an as yet unidentified ANT1-specific transcriptional or translational processing error. ANT1 has also been associated with a third condition, autosomal dominant facioscapulohumeral muscular dystrophy (FSHD), an adult onset disorder characterized by variable muscle weakness in the face, feet, shoulders, and hips. FSHD patients possess specific DNA deletions on chromosome 4, which appear to cause derepression of several nearby genes, including ANT1. Early development of FSHD may involve mitochondrial dysfunction and increased oxidative stress, possibly associated with overexpression of ANT1. IUBMB Life, 57: 607-614, 2005 [source]

Thiamine-responsive megaloblastic anaemia: a cause of syndromic diabetes in childhood

PEDIATRIC DIABETES, Issue 4 2007
Birthe S Olsen
Abstract:, Thiamine-responsive megaloblastic anaemia (TRMA) is a rare autosomal recessive condition, characterized by megaloblastic anaemia, non-autoimmune diabetes mellitus, and sensorineural hearing loss. We describe three infants with TRMA from two consanguineous Pakistani families, who were not known to be related but originated from the same area in Pakistan. All children were homozygous, and the parents were heterozygous for a c.196G>T mutation in the SLC19A2 gene on chromosome 1q23.3, which encodes a high-affinity thiamine transporter. The result is an abnormal thiamine transportation and vitamin deficiency in the cells. Thiamine in high doses (100,200 mg/d) reversed the anaemia in all our patients. Two patients discontinued insulin treatment successfully after a short period, while the third patient had to continue with insulin. The hearing loss persisted in all three children. The diagnosis of TRMA should be suspected in patients with syndromic diabetes including hearing loss and anaemia, even if the latter is only very mild and, particularly, in the case of consanguinity. [source]

Partial deletion of the LAMA3 gene is responsible for hereditary junctional epidermolysis bullosa in the American Saddlebred Horse

ANIMAL GENETICS, Issue 1 2009
K. T. Graves
Summary Laminin 5 is a heterotrimeric basement membrane protein integral to the structure and function of the dermal,epidermal junction. It consists of three glycoprotein subunits: the ,3, ,3 and ,2 chains, which are encoded by the LAMA3, LAMB3 and LAMC2 genes respectively. A mutation in any of these genes results in the condition known as hereditary junctional epidermolysis bullosa (JEB). A 6589-bp deletion spanning exons 24,27 was found in the LAMA3 gene in American Saddlebred foals born with the skin-blistering condition epitheliogenesis imperfecta. The deletion confirms that this autosomal recessive condition in the American Saddlebred Horse can indeed be classified as JEB and corresponds to Herlitz JEB in humans. A diagnostic test was developed and nine of 175 randomly selected American Saddlebred foals from the 2007 foal crop were found to be carriers of the mutation (frequency of 0.026). [source]

Is informed choice in genetic testing a different breed of informed decision-making?

HEALTH EXPECTATIONS, Issue 2 2001
A discussion paper
Traditionally genetic counselling has promoted a non-directive approach to patients' decision-making but the feasibility of this has been questioned. Unlike most branches of medicine, which are shifting away from a paternalistic model, genetic counselling is approaching shared decision-making from a different perspective. There are certain features of genetic counselling and genetic testing which may complicate the drive towards shared decision-making and informed choice: 1. Genetic test results can have broader implications than non-genetic test results. 2. Genetic test results may be perceived by the patient differently to non-genetic test results. 3. Carrier status for autosomal recessive conditions may be difficult for patients to conceptualize. 4. Decisions in genetic counselling are often multiple and sequential. 5. Most information in genetic counselling is based on probabilities and uncertainties. Each of these features is discussed in relation to achieving shared decision-making in genetic testing and the implications for genetic counsellors are described. The points raised, however, have broader implications for medicine as several of the features, although central to genetic testing, are not entirely unique. Lessons learnt from genetic testing and genetic counselling in achieving shared decision-making could help develop methods of promoting informed choice in other medical arenas such as cancer screening. [source]