Médecine moléculaire et génétique

Prenatal and Postnatal Diagnostics of a Child with Bardet-Biedl Syndrome: Case Study

Abstract

Magdalena Pasińska, Lech Dudarewicz, Lucjusz Jakubowski and Olga Haus

Bardet Biedl Syndrome (BBS) is a rare, genetically determined syndrome which can result from a mutation in one of 19 known genes (often called BBS complex), which play a vital role in building structures and cell functions of cilia. Phenotypic symptoms of the syndrome usually progress in the first decade of life, however, they are characterized by a high diversity which makes their diagnosis difficult, especially in the early stage of life. The diagnosis is most frequently based on clinical symptoms and established in late childhood or adult life. BBS is a disorder of the non-motile cilia, which play the role of antennae receiving and transmitting sensory signals to photoreceptors of the retina, hearing cells or olfactory cells. Clinical symptoms of the disorders affecting these structures are: retinal pigmentary degeneration, polydactyly, learning difficulties, and formation of kidney, liver and pancreas cysts. The inheritance mode of BBS is in 80% autosomal recessive, which is connected with both parents carrying a mutated allele, and usually only giving birth to a symptomatic child defines a family as being at genetic risk, whith 25% risk of having another child with the disease and 50% of having offspring that are asymptomatic carriers For families with an identified mutation there exists a possibility of conducting prenatal or preimplementation genetic diagnosis in subsequent pregnancies The article presents a case of a patient in whom prenatal ultrasonography and subsequent clinical trials in post-natal period resulted in a Bardet-Biedl syndrome diagnosis, which was later confirmed through molecular tests.