Sickle cell disease and age at menarche in Jamaican girls: observations from a cohort study

Aims - (1) To investigate the distribution of age at menarche in a represen tative sample of 99 patients with homozygous sickle cell (SS) disease, 69 w ith sickle cell haemoglobin C (SC) disease, and 100 controls with a normal haemoglobin (AA) genotype followed in a cohort study from birth. (2) To exp lore the determinants of the age at menarche. Methods - Children ascertained in a newborn screening programme were follow ed prospectively from birth to age 18-26.5 years with regular assessments o f height, weight, pubertal stage, and haematological indices at the Sickle Cell Clinic of the University Hospital of the West Indies. Results - All subjects have now reached menarche and the mean age in normal controls (13.0 years) was significantly earlier than in SC disease (13.5 y ears) or SS disease (15.4 years). Greater weight and earlier age at menarch e was the only association significant across all genotypes although additi onal contributions occurred from fetal haemoglobin and red cell count in SS disease. Alpha thalassaemia, which ameliorates many of the effects of SS d isease, had no discernible effect on menarche. Conclusions - Mean age at menarche is delayed by 0.5 years in SC disease an d by 2.4 years in SS disease. Weight appears to be the principle determinan t of age at menarche.