Androgen receptor CAG and GGC polymorphisms in Mediterraneans: repeat dynamics and population relationships.

Microsatellite variation (CAG and GGC repeats) of the androgen receptor (AR) gene shows remarkable differences among African and non-African populations. In vitro studies have demonstrated an inverse relationship between the length of both microsatellites and AR activity. This fact may explain the observed association of the AR gene with prostate cancer and the strong ethnic differences in the incidence of this cancer. CAG and GGC genetic variation has been tested in a large set of populations from the Ivory Coast as well as 12 Mediterranean samples whose variation is described for the first time. The pattern of frequencies observed in the Ivory Coast agrees with data previously reported for other Sub-Saharan populations. Concerning the Mediterranean variation, Sardinian samples are characterised by low genetic diversities, and Egyptian Siwa Berbers by a particular pattern of GGC frequencies. High and Middle Atlas Moroccan Berbers are the most closely related to the Sub-Saharan variation. For both the CAG and GGC repeats, the Ivory Coast and some Moroccan samples exhibit high frequencies of low size alleles (CAG under 18 repeats, and GGC under 15 repeats) that have been associated with prostate cancer.

Angiotensin I converting enzyme polymorphism effects in patients with normal pressure hydrocephalus syndrome before and after surgery.

Previous reports have suggested an association between the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE), cardiovascular disease, and cognitive performance. Normal pressure hydrocephalus (NPH) is considered to be an example of reversible dementia although the clinical improvement after shunting varies from subject to subject. An association has been suggested between vascular risk factors and the development of NPH. The ACE plays a major role in vascular pathology and physiology. In the present study we investigated the distribution of an ACE gene insertion/deletion polymorphism in 112 patients diagnosed with NPH and in 124 controls. We also evaluated the role of this genetic polymorphism in cognitive functioning before and following surgery in a subgroup of 72 patients. No differences in genetic or allele distributions were found between patients and healthy subjects, but among patients, carriers of D/D or D/I genotypes obtained less cognitive benefit following shunt surgery, especially on measures of memory and frontal function. Our data support previous findings in other conditions indicating that possession of at least one D allele is associated with poorer cognitive performance.