Chromosome autosomes

Figure 19.2 A human somatic cell contains two sets of homologous chromosomes, which may be divided into two types autosomes and sex chromosomes. Autosomes are further divided into seven groups A-G. During the metaphase of cell division, each chromosome has been duplicated. Therefore, this karyotype consists of 92 chromosomes.

AATAACATAG)3 5 -CCCGTACTGGT CCCGTACTGGT 2L and 3L 1.5-2 Mb per chromosome autosomal centromeres 1.686 g/cm satellite... 

Parkin is a ubiquitin ligase encoded by a gene affected in autosomal recessive juvenile parkinsonism (AR-JP). This gene is located on chromosome 6 and encodes a protein of 465 amino acid residues with moderate similarity to ubiquitin at the amino terminus and a RING-finger motif at the carboxy terminus. 

While it is probably rarer than recessively inherited disease, families with autosomal dominant LGD have been described, and in these families the disease is usually relatively mild. In one large family with dominant disease and the unusual additional feature of dysarthria, a locus has been identified on chromosome 5. The genes responsible for this condition in other families have not yet been localized. 

Transmission is autosomal dominant, and the relevant gene has been mapped to the same locus on chromosome 19q as that associated with susceptibility to malignant hyperthermia (pages 318-319). It is not established that the conditions are allelic. Almost all patients with CCD whose muscle has been tested in vitro for... 

Genetic transmission in nemaline myopathy is the subject of some uncertainty. A Japanese study of 50 pedigrees came to the conclusion that autosomal dominant with reduced penetrance was the most probable mode. However a Finnish study presented evidence for autosomal recessive transmission. There is no evidence that severe and mild forms are genetically distinct and several pedigrees contain members showing widely differing clinical severity. A candidate gene for autosomal dominant nemaline myopathy has been localized to chromosome Iq 21—23. 

All three forms of spinal muscular atrophy are inherited as autosomal recessive disorders, linked to chromosome 5q. Prenatal diagnosis using closely linked markers is now available. A rare, autosomal dominant form of juvenile SMA is similar in expression to the recessive forms, but 5q is not involved. 

In patients with ataxia-telangiectasia, an autosomal recessive disease in humans resulting in the development of cerebellar ataxia and lymphoreticular neoplasms, there appears to exist an increased sensitivity to damage by x-ray. Patients with Fanconi s anemia, an autosomal recessive anemia characterized also by an increased frequency of cancer and by chromosomal instability, probably have defective repair of cross-linking damage. 

Figure 52-7. Simplified scheme of the sequence of events involved in the causation of chronic granulomatous disease (MIM 306400). Mutations in any of the genes for the four polypeptides involved (two are components of cytochrome b55gand two are derived from the cytoplasm) can cause the disease. The polypeptide of 91 kDa is encoded by a gene in the X chromosome approximately 60% of cases of chronic granulomatous disease are X-linked, with the remainder being inherited in an autosomal recessive fashion.

Chromosomal Disorders Autosomal Trisomy 21 Trisomy 18 Trisomy 13 Translocations Deletions ... 

Genetic Familial prostate cancer is inherited in an autosomal dominant manner. Mutations in p53, Rb, E-cahedrin, a-catenin, androgen receptor, KAII, microsatellite instability, loss of heterozygocity at 1, 2q, 12p, 15q, 16p, and 16q. Candidate prostate cancer gene locus identified on chromosome 1. 

Chromosome A subnuclear structure comprising DNA and associated proteins. Apart from the sex cells, each human cell has 23 pairs of chromosomes comprising 22 autosomes and a pair of sex chromosomes (XX in females, XY in males). 

Autosome A chromosome not involved in sex determination. The diploid human genome consists of 46 chromosomes, 22 pairs of autosomes, and one pair of sex chromosomes (X and Y chromosomes). 

Friedreich s ataxia is caused by an intronic triplet repeat expansion. Friedreich s ataxia is an autosomal recessive disorder characterized by progressive ataxia, nystagmus, distal sensory polyneuropathy and corticospinal tract degeneration. It is caused by an unstable expanded GAA repeat in intron 1 of the frataxin gene on chromosome 9ql3. This diminishes expression of frataxin, a mitochondrial iron-storage protein that participates in free radical metabolism [71]. 

Chance, P. F., Abbas, N., Lensch, M. W. et al. Two autosomal dominant neuropathies result from reciprocal DNA dupli-cation/deletion of a region on chromosome 17. Hum. Mol. Genet. 3 223-228,1994. 

Matsumine, H., Saito, M., Shimoda-Matsubayashi, S. et al. Localization of a gene for an autosomal recessive form of juvenile Parkinsonism to chromosome 6q25.2-27. Am. J. Hum. Genet. 60 588-596,1997. 

Van Duijn, C. M., Dekker, M. C., Bonifati, V. et al. Park7, a novel locus for autosomal recessive early-onset parkinsonism, on chromosome lp36. Am. J. Hum. Genet. 69 629-634, 2001. 

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