Bardet-Biedl syndrome in two sibling pairs: a case series.

This research report describes four children from two Pakistani families who were diagnosed with Bardet-Biedl Syndrome (BBS) based on their symptoms, since genetic testing wasn't available. The study looked at two pairs of siblings - two brothers aged 17 and 21 from one family, and a 9-year-old boy with his 4.5-year-old sister from another family. All the children showed classic BBS features like vision problems, obesity, extra fingers or toes (polydactyly), and developmental delays, but each child had a different combination and severity of symptoms. The key finding was that even within the same family, BBS can look quite different from one sibling to another. For example, one brother had serious kidney problems while his sibling's kidneys were normal. This variation makes diagnosis challenging, especially in areas where genetic testing isn't readily available. The doctors used clinical checklists and careful examination of symptoms to make the diagnosis instead of relying on genetic tests. This research is important because it shows that doctors can still accurately diagnose BBS using clinical guidelines when genetic testing isn't an option. Early diagnosis is crucial because it allows families to get the right medical care and support services for vision problems, kidney issues, developmental delays, and other complications. The study emphasizes the need for a team approach to care, involving different specialists to address the various aspects of this complex condition.

Bardet-Biedl syndrome is a rare multisystem ciliopathy defined by retinal dystrophy, obesity, polydactyly, hypogonadism, and renal anomalies, often accompanied by neurodevelopmental and behavioral issues. Diagnosis relies heavily on clinical features, particularly in resource-limited settings where genetic testing is unavailable. We describe two sibling pairs, all of South Asian, Pakistani ethnicity, clinically diagnosed with Bardet-Biedl syndrome using contemporary diagnostic frameworks. The first pair, two male brothers aged 17 and 21 years, came from a consanguineous family. The 17-year-old male presented with edema, polyuria and polydipsia, progressive night blindness, morbid obesity, polydactyly, hypogonadism, and retinopathy. Further investigations revealed renal impairment, and he was classified as definite Bardet-Biedl syndrome. His 21-year-old male brother had longstanding weight gain, striking polydactyly of the hands and feet, hypertension, moon facies, micropenis with gynecomastia, obesity, and behavioral disturbances including aggression and social withdrawal, along with nyctalopia and reduced visual acuity. His renal function was normal, and he was categorized as probable-to-definite Bardet-Biedl syndrome. The second pair, a 9-year-old male brother and a 4.5-year-old female sister, belonged to a nonconsanguineous Pakistani family. The brother exhibited decreased vision from early childhood, recurrent chest infections, urinary frequency, obesity with acanthosis, left-sided hand and foot polydactyly, micropenis, speech delay, and learning difficulties. Ultrasound findings showed normal kidneys and laboratory tests were within range, and he was considered definite Bardet-Biedl syndrome. His 4.5-year-old female sister presented with rapid weight gain, polyphagia, nyctalopia, reduced vision, behavioral dysregulation including hyperactivity, social and language delay, urinary frequency with enuresis, and microscopic hematuria on urinalysis despite normal renal size. She was categorized as probable Bardet-Biedl syndrome. This series highlights the significant intrafamilial variability of Bardet-Biedl syndrome and underscores the value of systematic clinical frameworks for early diagnosis and multidisciplinary management in settings where genetic confirmation is not available.