Tibia vara in a patient with Bardet-Biedl syndrome

Musculoskeletal Manifestations in Patients With Bardet-Biedl Syndrome: A Report of Two Cases

We report two patients with musculoskeletal manifestations as part of the Bardet-Biedl syndrome. The first patient (case 1) was born with polydactyly and later diagnosed with coxa vara. He had homozygous pathogenic mutation in the BBS1 gene of the variant c.1645G>T (p.Glu459*). The second patient (case 2) had nyctalopia and progressive vision worsening had osteoarthritis symptoms. He had a heterozygous mutation in the BBS1 gene of the variant c.1169T>G (p.Met390Arg). Although polydactyly is the most prevalent musculoskeletal association in patients with the syndrome, co-management of the musculoskeletal manifestations remains of utmost importance in patients with the syndrome.

Orthopaedic manifestations of Bardet-Biedl syndrome

Bardet-Biedl syndrome is an autosomal recessive disorder poorly characterized in the orthopaedic literature. Classic manifestations of the syndrome include pigmentary retinopathy, obesity, polydactyly, hypogonadism, and mild mental retardation. Previous reports have implied that orthopaedic findings are due to an epiphyseal dysgenesis inherent to the syndrome. The purpose of this study was to evaluate the orthopaedic manifestations of 27 patients with this syndrome. Detailed medical histories and physical examinations as well as pedigree analyses and radiographic bone surveys were performed. Orthopaedic findings included the following: 17 patients had postaxial polydactyly, 4 patients had scoliosis, 2 patients had tibia valga, 2 patients had tibia vara, and 1 patient had Legg-Calve-Perthes. The bone survey did not reveal any additional radiographic abnormalities. Based on these results, Bardet-Biedl syndrome patients do not have epiphyseal dysgenesis; their epiphyseal manifestations are probably the result of their obesity.

A review of the literature of Bardet-Biedl disease and report of three cases associated with metabolic syndrome and diagnosed after the age of fifty

Bardet-Biedl syndrome (BBS) is a genetic autosomal-recessive disease (formerly grouped with Laurence-Moon-Biedl syndrome but considered today as a separate entity) characterized by abdominal obesity, mental retardation, dysphormic extremities (syndactyly, brachydactyly or polydactyly), retinal dystrophy or pigmentary retinopathy, hypogonadism or hypogenitalism (limited to male patients) and kidney structural abnormalities or functional impairment. The expression and severity of the various clinical BBS features show inter- and intrafamilial variability. This study focuses on three cases of familial BBS--two sisters and one brother (66, 64 and 51 years of age, respectively)--with the main cardinal findings of the disease plus a classic 'metabolic syndrome' (characterized by abdominal obesity, atherogenic dyslipidaemia, raised blood pressure, insulin resistance with or without glucose intolerance, and prothrombotic risk and proinflammatory states). One female patient (not affected by reproductive dysfunction) had three healthy offspring, while the other two patients were unmarried. Another severely affected brother died at 70 years of age; two other brothers are lean but affected by nephropathy, retinopathy, slight mental retardation, polydactyly, hypertension and thrombotic diseases, and had healthy offspring. BBS is a rather rare but severe syndrome that is often mis- or undiagnosed. Ophthalmologists, endocrinologists and nephrologists should be aware of BBS because of its adverse prognosis--early onset of blindness, associated findings of metabolic syndrome and increased vascular risk, and severe renal impairment (the most frequent cause of reduced survival and death early in life).