Comparative study of Fanconi anemia in children of different ethnic origin in South Africa.

A comparative study of clinical, hematologic, and cytogenetic findings was made in 40 black and 35 white children with Fanconi anemia. The black children were Bantu-speaking Negroid stock of diverse tribal origin. The white children were predominantly Afrikaans stock of Dutch/German/French Huguenot origin. All of the patients had IFAR scores of 2 to 4+ and over 80% in each group had increased spontaneous and/or mutagen-induced chromosomal breakage (CB-positive). There were no significant clinical differences between black and white patients or between CB-pos and CB-neg patients, with the exception of white children in whom significantly more CB-pos patients had thumb and radial anomalies than the CB-neg patients. The age-at-onset of hematologic manifestations was the same for all groups, but more black than white CB-pos patients were severely anemic at the time of diagnosis. Response to androgen and steroid therapy occurred in only 33% of black children compared with 86-90% of white children; 81% of black patients died during the 18 year study period compared with 30% of white children, but the age at death was similar. More sophisticated studies are required to determine whether these differences are genetically determined or related to cultural, educational, and socio-economic differences between the two ethnic groups.