Congenital absence of gonadotropin releasing hormone in the hypothalamus (causing, in women, primary amenorrhea and anovulation and, in men, failure of puberty) in combination with a congenitally absent sense of smell.

A test that displays the chromosome after relevant cells are grown in tissue culture. A normal female karyotype is designated 46,XX and a normal male karyotype 46,XY.

A trisomy with a karyotype of 47,XXY -- i.e. a male with an extra X-chromosome. A cause of azoospermia.

An in vitro (laboratory) test of the interaction between sperm and cervical mucus, in which the mucus to be tested is drawn into two fine glass tubes (another two tubes are filled with mucus that is known to be good) to give a 4-way test between: husband's (or male partner's) sperm and wife's (or female partner's) mucus; husband's sperm and known good mucus; known good sperm with wife's mucus; known good sperm with known good mucus. Because of the laboriousness of the test it's usual to administer estrogen for at least a week in the follicular phase to ensure that the mucus is optimal.

A reproductive strategy where survival of a species is optimised by placing a premium on individual survival despite fluctuations of the environment. Favors large animals (and large animals favor this strategy) -- animals that get pregnant more than once and the offspring of which require postnatal care before sexual maturity is reached. Spacing of pregnancy is important for survival of mother and offspring, and thus favors the evolution of a genetic basis for subfertility. The opposite reproductive strategy to r-selection. The word comes from the environment's Karrying capacity.