Alkaptonuria

Alkaptonuria is found relatively frequently in Slovakia, Eastern Czechoslovakia (1 in 25,000 inhabitants). Reported herein are the clinical, radiographic, and biochemical aspects and genetics of 126 patients with alkaptonuria. Forty-seven were diagnosed in childhood; the sequential appearance of each manifestation is documented by decade. A simple screening method for this disorder is described. Pedigree analyses confirm recessive inheritance. Possible genetic and sociologic factors responsible for this high frequency of alkaptonuria are discussed.

Alkaptonuria in the Trencín District of Czechoslovakia

For several years the Clinical Genetics Research Laboratory at Martin, Czechoslovakia, has been studying alkaptonuria (AU) in the northern part of the District of Trencín in Slovakia. These affected individuals are part of a group of 103 alkaptonurics originated mostly in the mountainous parts of Slovakia. We report results of pedigree analyses; population and affected-family biochemical urine screening; estimation of inbreeding coefficient, of exogamy rate and of average marital distance and of calculation of the frequency of the AU allele, and of homozygotes and heterozygotes in this portion of the Trencín District. Twelve homozygotes were found, but seven originated from a single hamlet in which a founder effect - genetic drift and inbreeding - are thought to account for the high prevalence of AU.

[HLA-B27 antigen and alkaptonuria]

Study of urinary homogentisic acid and a determinantion of group HLA were carried out for 36 members of a family spread over three generations with three cases of ochronotic rheumatism in the second generation. Alkaptonuria was discovered in seven other subjects, six of them members of the third generation: urinary elimination was poor, less than 0.60 g/24 hours. There is a certain degree of consanguinity in the family studied here and these findings do not therefore rule out a recessive autosomal transmission of the alkaptonuria. They do however lead to the consideration that alkaptonuria may sometimes be found in heterozygotic subjects. A genetic relationship between HLA complex and alkaptonuria can only be claimed with difficulty from this familial study, but the high frequency of B 27 antigen (29 out of 36 members carring it) leaves room for the hypothesis that the B 27 gene, or more precisely a gene associated with the B 27 gene, plays a part in the development of ochronotic rheumatism.

Osler as a medical geneticist

Osler's immediate successor as Regius Professor at Oxford was Archibald Garrod (1857-1936), the founder of biochemical genetics. Like Mendel's, Garrod's concepts and discoveries were late in gaining wide currency and had in effect ot be rediscovered by Beadle and Tatum and by the students of biochemical individuality in the 1950s and 1960s. I have attempted to show that Garrod's predecessor Regius also contributed to medical genetics--not to its theoretical roots, to be sure, but certainly in an important way to the nosology of genetic disease.