To determine the interfamilial and intrafamilial variation in the expression of the Bardet-Biedl syndrome (a form of Laurence-Moon-Biedl syndrome), we looked for the five recognized features of the disorder (retinal dystrophy, obesity, polydactyly, mental retardation, and hypogonadism), plus possible renal manifestations, in some or all of 32 patients with this disorder. All 28 patients examined had severe retinal dystrophy, but only 2 had typical retinitis pigmentosa. Polydactyly was present in 18 of 31 patients, but syndactyly, brachydactyly, or both were present in all. Obesity was present in all but 1 of 25 patients. Only 13 of 32 patients were considered mentally retarded. Scores on verbal subtests of intelligence were usually lower than scores on performance tasks. Seven of eight men had small testes and genitalia, which was not due to hypogonadotropism. All 12 women studied had menstrual irregularities, and 3 had low serum estrogen levels (1 of these had hypogonadotropism, and 2 had primary gonadal failure). The remaining women who were of reproductive age had endocrinologic evidence of reproductive dysfunction. Diabetes mellitus was present in 9 of 20 patients. Renal structural or functional abnormalities were universal (n = 21), and three patients had end-stage renal failure. We conclude that the characteristic features of Bardet-Biedl syndrome are severe retinal dystrophy, dysmorphic extremities, obesity, renal abnormalities, and (in male patients only) hypogenitalism. Mental retardation, polydactyly, and hypogonadism in female patients are not necessarily present.

We report on a patient with congenital absence of the left pectoralis major muscle, whose second cousin had the full Poland sequence. This suggests that isolated pectoralis major muscle defect should be included in the spectrum of anomalies characterized as the Poland sequence, postulated to result from disruption of blood supply in the embryonic subclavian and vertebral arteries, the site and degree of obstruction determining the sites and severity of the resulting anomalies. Very few cases are familial; in these the family pattern is compatible with an autosomal dominant mutant gene with reduced penetrance or delayed mutation.

There are at least five distinct Bardet-Biedl syndrome (BBS) loci, four of which have been mapped: 11q (BBS1), 16q (BBS2), 3p (BBS3), and 15q (BBS4). A comparative study of the three Arab-Bedouin kindreds used to map the BBS2, BBS3, and BBS4 loci suggests that the variability in the number and severity of clinical manifestations, particularly the pattern of polydactyly, reflects chromosome-specific subtypes of BBS [Carmi et al., 1995a; Am J Med Genet 59:199-203]. We describe a Newfoundland kindred of northern European descent and confirm the initial finding of a BBS locus on chromosome 3. However, the "BBS3 phenotype," which includes polydactyly of all four limbs and a progression to morbid obesity, was not observed. Rather, four of the five BBS patients in this family had polydactyly restricted to their feet. The obesity in these patients was reversible with caloric restriction and/or exercise. Mental retardation has been considered a major symptom of BBS. However, formal IQ testing shows that these patients are of average intelligence. Haplotype analysis reduces the BBS3 critical region to a 6-cM interval between D3S1595-D3S1753.

A simple method was devised for recording dermatoglyphics in a form suitable for sweat pore counting. Fifteen members of a family with a hypohidrotic X‐linked ectodermal dysplasia made their own hand prints using our method and mailed the results to us for interpretation. The simplicity of the technique also makes it practical to use on new‐born males at risk for the condition, or where dermatoglyphic records are required for other purposes. Preliminary data suggest that patchiness of sweat pore distribution on the fingers and palms may be useful in the discrimination of heterozygotes.