Acute myelomonocytic leukaemia following atypical congenital rubella.

The child of a woman immunised against rubella presented at 5 months with developmental delay and recurrent infection; she was shown to have congenital rubella. At 15 months she developed acute myelomonocytic leukaemia (AMML). Rubella is difficult to diagnose after immunisation. AMML has not been previously described in association with congenital rubella, as far as is known.

Congenital leptin deficiency is associated with severe early-onset obesity in humans.

The extreme obesity of the obese (ob/ob) mouse is attributable to mutations in the gene encoding leptin, an adipocyte-specific secreted protein which has profound effects on appetite and energy expenditure. We know of no equivalent evidence regarding leptin's role in the control of fat mass in humans. We have examined two severely obese children who are members of the same highly consanguineous pedigree. Their serum leptin levels were very low despite their markedly elevated fat mass and, in both, a homozygous frame-shift mutation involving the deletion of a single guanine nucleotide in codon 133 of the gene for leptin was found. The severe obesity found in these congenitally leptin-deficient subjects provides the first genetic evidence that leptin is an important regulator of energy balance in humans.