Polydactyly and partial blindness.

Accepted 20 March 1997 During a survey for diabetes mellitus in rural India, a 34-year-old man with polydactyly and partial blindness drew the attention of this author. He was born of a consanguineous marriage and had healthy siblings. His parents report that the milestones of developments were apparently normal up to the age of four years when they noticed his difficulty in identifying objects and moving in familiar surroundings, initially at night but progressing. He was obese, did not attend school and was looking after the animal farm with accidental injuries. Secondary sexual hair growth was complete by 16 years. There was no history of polyuria, polydipsia or weight loss nor any symptoms to suspect renal failure. There was no family history of diabetes. On further enquiry, his niece born of consanguineous marriage had a similar history. On examination, he weighed 68.5 kg with a height of 1.55 m and a body mass index of 28.5. Hexadactyly affecting the feet and brachydactyly of both the extremities were obvious. Injury marks were seen on both shins (figure). Simple assessment of higher functions revealed his inability to repeat four digits forwards and three digits backwards. Ophthalmologic review confirmed his inability to count fingers and limitation of vision to hand movements. Fundus showed pigmentary changes all over in both the eyes with pale discs. Examination of the genitourinary system revealed microphallus and an empty scrotal sac. Urine was checked for glucose and proteinuria and these were negative. Capillary blood glucose after a 75 g glucose load was normal (7.2 mmol/l). His condition has been explained to his parents and the potential dangers of cryptorchidism but intervention has been refused. His niece also was obese, had polydactyly of feet, brachydactyly, myopic disc with pigmentary dystrophy and normal glucose tolerance.