Article Abstract:
A high rate of parental consanguinity exists in cytochrome-oxidase deficiency, standing at 10%-30%. Studying 157 patients from 148 families it was found that the most common causes of respiratory chain defects in childhood are complex I, complex !V and complex I+IV, at 33%, 28% and 28%, respectively. Autosomal recessive inheritance is involved in most cases of mitochondrial childhood disorders. Genetic counseling would be in order. In North African families a rate of inbreeding higher still was seen. With parental consanguinity related to geographic origin there is a greater effect.
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Article Abstract:
A study of mutations in 16 patients with Cockayne syndrome found no relation between clinical severity and size or nature of mutations. Mutations in the CSB gene were studied. Nine patients had truncated products in both alleles, whereas the other seven had at least one allele with a single changed amino acid. Eighteen inactivating mutations were identified altogether. The syndrome results in an inability to repair active genes after UV irradiation.
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Article Abstract:
Studies of Italian trichothiodystrophy patients indicate that the severity of symptoms is regulated by gene dosage in the mutation rather than mutation site. Although the mutation site is linked with repair deficiency, the hair abnormalities such as cellular photosensitivity correspond to unique mutations in the xeroderma pigmentosum gene, resulting in disease alleles.
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