Genetic deficits

The complexity of the genetic basis of DPD deficiency implies that the identification of patients at high risk of 5-FU toxicity is mostly based on phenotypic procedures. These methods are not suitable for general use and concomitant drags, dietary intake and other environmental factors could reduce their predictive power in cases of partial DPD deficit. 

Spontaneous mutations in experimental animals provide insights about the structure and assembly of myelin. The myelin mutants often have names relating to their characteristic tremor due to the myelin deficit, e.g. shiverer, jimpy, quaking and trembler mice (Table 4-2). Although some of the mutants have been studied for many years [1], it is only recently that recombinant DNA techniques have led to identification of the primary genetic defects in most of them. Some of them are good... 

Gornick, M. C., Addington, A., Shaw, P., et al. (2007) Association of the dopamine receptor D4 (DRD4) gene 7-repeat allele with children with attention-deficit/hyperactivity disorder (ADHD) an update. Am. J. Med. Genet. 144, 379-382. 

Hawi, Z., Segurado, R., Conroy, J., et al. (2005) Preferential transmission of paternal alleles at risk genes in attention-deficit/hyperactivity disorder. Am. J. Hum. Genet. 77,... 

Eullerton, S.M., Clark, A.G., Weiss, K.M., et al. (2002) Sequence polymorphism at the human apolipoprotein All gene (APOA2) unexpected deficit of variation in an African-American sample. Hum. Genet., Ill, 75-87. 

The cause of Alzheimer s disease is unknown, but genetic factors clearly play a role. One clue supporting this view is provided by the observation that individuals with Down syndrome, a common cause of mental retardation, frequently develop a dementia similar to Alzheimer s disease during early adulthood. Vascular dementia, which is also called multi-infarct dementia, results from the accumulation of tiny strokes. Individually, these strokes or infarcts are too small to cause any noticeable problem, but as they accumulate, they produce deficits similar to Alzheimer s disease. Other neurological diseases such as Parkinson s disease, Pick s disease, and Huntington s disease cause slow deterioration of the brain that ultimately leads to a degenerative dementia. 

Couldrey, C., Carlton, M.B.L., Nolan, P.M., CoUedge, W.H., and Evans, M.J. (1999) A retroviral gene trap insertion into the histone 3.3A gene causes partial neonatal lethality, stunted growth, neuromuscular deficits and male sub-fertility in transgenic mice. Hum. Mol. Genet. 8,... 

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