Síndrome de Bardet Biedl: a propósito de un caso / Bardet Biedl syndrome: a case report

El síndrome de Bardet Biedl es un síndrome genético de herencia autosómica recesiva con compromiso multisistémico y gran variabilidad en su presentación clínica; son características la obesidad, la polidactilia, el hipogonadismo y las alteraciones renales, visuales y cognitivas. Pertenece a las llamadas ciliopatías. El diagnóstico es clínico y puede ser confirmado por estudios genéticos. No existe un tratamiento específico de la patología; se requiere un abordaje multidisciplinario. Se presenta el caso de una paciente de 13 años con obesidad e hiperfagia, diabetes tipo 2, hipotiroidismo, polidactilia, alteraciones del aprendizaje y alteraciones visuales. Se le realizó un panel genético para obesidad en el que se detectaron dos variantes heterocigotas patológicas en el gen BBS2.

Bardet Biedl syndrome is an autosomal recessive ciliopathie. It is a pleiotropic disorder characterised by retinal dystrophy, renal dysfunction, polydactyly, obesity, cognitive deficitand hypogenitalism. Diagnosis is based on clinical features. Molecular genetic testing is available. There is no specific treatment, a multidisciplinary approach is required. We report the case of a 13-year-old female patient with obesity and hyperphagia, type 2 diabetes, hypothyroidism, polydactyly,cognitive deficit and visual impairment. A multigenic panel allowed the identification of two heterozygous pathogenic variants in the BBS2 gene.

Síndrome de Bardet-Biedl: série de caso e revisão da literatura / Bardet- Biedl Syndrome: case series and literature revision

Resumo A Síndrome de Bardet-Biedl é uma desordem autossômica recessiva rara, com heterogeneidade clínica e genética. As principais características são retinopatia pigmentar, obesidade, polidactilia, dificuldades de aprendizado, diversos graus de deficiência intelectual, anomalias renais e hipogonadismo. O objetivo desse trabalho é relatar dois casos de síndrome de Bardet-Biedl em pacientes diagnosticados no Instituto Benjamin Constant e fazer uma revisão literária da síndrome. Revisão de prontuário e pesquisa bibliográfica nas bases de dados do PubMed, SciELO, MEDLINE e LILACS. Atualmente não há tratamento para a Síndrome de Bardet-Biedl, mas o diagnóstico precoce é importante para orientar a gestão da criança através de uma avaliação regular da pressão arterial, peso, estudos de imagiologia renais, exames oftalmológicos e apoio psicológico.

Abstract The Bardet-Biedl Syndrome is a rare autosomal recessive disorder with clinical and genetic heterogeneity. Its main characteristics are pigmentary retinopathy, obesity, polydactyly, learning disabilities, various degrees of intellectual disability, renal anomalies and hypogonadism. The objective of this study is to report two cases of the Bardet-Biedl syndrome in patients diagnosed at the Benjamin Constant Institute and to perform a literary review of the syndrome. Review of medical records and bibliographic research were made from the PubMed, SciELO, MEDLINE and LILACS databases. Currently, treatment for the Bardet-Biedl Syndrome does not exist, but early diagnosis is important to guide the child through a regular assessment of blood pressure, weight, renal imaging studies, eye exams and psychological support.

Variante patogénica homocigótica del gen BBS10 en un paciente con síndrome de Bardet-Biedl / A pathogenic homozygous variant of the BBS10 gene in a patient with Bardet Biedl syndrome

Resumen El síndrome de Bardet-Biedl es una enfermedad hereditaria, autosómica recesiva, con gran heterogeneidad de locus, que pertenece a las denominadas ciliopatías, denominadas así por la deficiencia funcional presente y porque las proteínas afectadas se localizan en el cilio primario. El síndrome afecta múltiples sistemas, con compromiso visual, renal, cognitivo, esquelético y gonadal, y obesidad. Este síndrome presenta una gran variabilidad intrafamiliar e interfamiliar. Se presenta el caso clínico de un paciente adolescente con diagnóstico de síndrome de Bardet-Biedl, así como su manejo, los resultados de la secuenciación de 22 genes y el análisis actualizado de la literatura médica. Se recopiló la información clínica y, previo consentimiento informado, se hizo la prueba de panel de secuenciación multigénica de los genes implicados. El paciente es hijo de la unión de personas consanguíneas. Fue el primer afectado en la familia y presentaba polidactilia posaxial, obesidad, micropene, retinitis pigmentaria y dificultades de aprendizaje. En el panel multigénico, se identificó la variante patogénica homocigótica c.39_46del en el gen BBS10 y otras variantes de genes BBS asociadas con la obesidad. Dado que el síndrome de Bardet-Biedl es una enfermedad huérfana rara, interpretar el pleiotropismo y la heterogeneidad de locus y de alelos, constituye un reto. La confirmación molecular permite el manejo adecuado de los pacientes, así como el seguimiento y el asesoramiento genético apropiados.

Abstract The Bardet-Biedl syndrome is an autosomal recessive hereditary disorder with vast locus heterogeneity that belongs to the so-called ciliopathies, whose proteins are localized in the primary cilia and present functional deficiency. The multisystemic features of the disease include ocular, renal, cognitive, skeletal, as well as gonadal involvement and obesity, among others, with high inter- and intrafamilial variability. We describe the clinical case of an adolescent male patient with Bardet-Biedl syndrome, including the approach, the results from a 22-gene sequencing panel, and the analysis of updated scientific literature. We collected the clinical data of the patient and, after obtaining the informed consent, we conducted a multigenic sequencing panel oriented to known implicated genes. The patient was born to consanguineous parents and was the first affected member of the family. He presented with postaxial polydactyly, obesity, micropenis, retinitis pigmentosa, and learning disability. The multigenic panel allowed the identification of the homozygous pathogenic variant c.39_46del in the BBS10 gene and in other BBS genes variants associated with obesity. As the Bardet-Biedl syndrome is a rare disease, it is challenging to interpret its pleiotropism and gene/allelic heterogeneity. Its confirmation by molecular tests allows an adequate approach, follow-up, and genetic counseling of the patient and the family.

Hypokolemic paralysis and megaloblastic anaemia in laurence-moon-bardet-biedl syndrome

Laurence-Moon-Bardet-Biedl syndrome is a rare, genetically heterogeneous autosomal recessive disorder, characterized by progressive retinal dystrophy, polydactyly, obesity, hypogonadism, mental retardation, and renal dysfunction. Other manifestations include diabetes mellitus, heart disease, hepatic fibrosis and neurological features. Herein, 2 patients with Laurence-Moon-Bardet-Biedl syndrome are described, who had features of persistent hypokalemia and megaloblastic anemia