Nephrological aspects of Bardet-Biedl syndrome in pediatric practice: a clinical case and literature review

Abstract

Bardet-Biedl syndrome (BBS) is an autosomal recessive ciliopathy characterized by retinitis pigmentosa, obesity and related complications, postaxial polydactyly, cognitive impairments, hypogonadotropic hypogonadism and/or genitourinary anomalies, as well as developmental defects and/or parenchymal diseases of the kidneys. Traditionally, diagnosis of BBS has relied on the presence of clinical manifestations, with subsequent confirmation through genetic testing. However, clinical features of BBS manifest at various ages, which may delay diagnostic processes. The average age of BBS diagnosis is 8–9 years, but the presence of congenital renal anomalies together with other features, such as polydactyly or syndactyly, which can be detected prenatally or at birth, provides grounds for including BBS in the differential diagnosis much earlier. Additionally, the presence of renal and genitourinary anomalies results in chronic kidney disease (CKD). In some patients, CKD may progress to renal failure, which is the main cause of mortality among individuals with BBS. This article presents data on possible manifestations of BBS, the role of kidney injury in its diagnosis, as well as other syndromes and clinical features that require differentiation from BBS. A clinical case is also described of a patient with BBS presenting with polydactyly, retinal dystrophy, overweight, other congenital anomalies, and, notably, renal involvement, which enabled suspicion and diagnosis of BBS at the age of 3 years. Although BBS has no specific treatment, early detection allows for the involvement of a multidisciplinary team in patient management and may reduce the risk of severe complications, such as CKD.