RESUMEN
Joubert syndrome (JS) and related disorders (JSRD), Meckel syndrome (MKS) and Bardet-Biedl syndrome (BBS) are autosomal recessive ciliopathies with a broad clinical and genetic overlap. In our multiethnic cohort of 88 MKS, 61 JS/JSRD and 66 BBS families we performed genetic analyses and were able to determine mutation frequencies and detection rates for the most frequently mutated MKS genes. On the basis of determined mutation frequencies, a next generation gene panel for JS/JSRD and MKS was established. Furthermore 35 patients from 26 unrelated consanguineous families were investigated by SNP array-based homozygosity mapping and subsequent DNA sequencing of known candidate genes according to runs of homozygosity size in descending order. This led to the identification of the causative homozygous mutation in 62% of unrelated index cases. Based on our data we discuss various strategies for diagnostic mutation detection in the syndromic ciliopathies JS/JSRD, MKS and BBS.
Asunto(s)
Anomalías Múltiples/genética , Síndrome de Bardet-Biedl/genética , Cerebelo/anomalías , Trastornos de la Motilidad Ciliar/genética , Encefalocele/genética , Anomalías del Ojo/genética , Pruebas Genéticas/métodos , Enfermedades Renales Quísticas/genética , Mutación , Enfermedades Renales Poliquísticas/genética , Retina/anomalías , Anomalías Múltiples/etnología , Síndrome de Bardet-Biedl/etnología , Trastornos de la Motilidad Ciliar/etnología , Consanguinidad , Encefalocele/etnología , Anomalías del Ojo/etnología , Femenino , Predisposición Genética a la Enfermedad , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Enfermedades Renales Quísticas/etnología , Masculino , Tasa de Mutación , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Linaje , Enfermedades Renales Poliquísticas/etnología , Polimorfismo de Nucleótido Simple , Retinitis Pigmentosa , Análisis de Secuencia de ADN/métodosRESUMEN
Congenital disorders of glycosylation (CDG) are caused by a dysfunction of glycosylation, an essential step in the manufacturing process of glycoproteins. This paper focuses on a 6-year-old patient with a new type of CDG-I caused by a defect of the steroid 5α reductase type 3 gene (SRD5A3). The clinical features were psychomotor retardation, pathological nystagmus, slight muscular hypotonia and microcephaly. SRD5A3 was recently identified encoding the polyprenol reductase, an enzyme catalyzing the final step of the biosynthesis of dolichol, which is required for the assembly of the glycans needed for N-glycosylation. Although an early homozygous stop-codon (c.57G>A [W19X]) with no functional protein was found in the patient, about 70% of transferrin (Tf) was correctly glycosylated. Quantification of dolichol and unreduced polyprenol in the patient's fibroblasts demonstrated a high polyprenol/dolichol ratio with normal amounts of dolichol, indicating that high polyprenol levels might compete with dolichol for the initiation of N-glycan assembly but without supporting normal glycosylation and that there must be an alternative pathway for dolichol biosynthesis.
Asunto(s)
3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/genética , Trastornos Congénitos de Glicosilación/enzimología , Trastornos Congénitos de Glicosilación/genética , Proteínas de la Membrana/genética , Mutación/genética , Pentanoles/metabolismo , Células Cultivadas , Cromatografía Líquida de Alta Presión , Trastornos Congénitos de Glicosilación/diagnóstico , Dolicoles/metabolismo , Electroforesis en Gel de Poliacrilamida , Femenino , Fibroblastos , Prueba de Complementación Genética , Glicosilación , Homocigoto , Humanos , Inmunoprecipitación , Recién Nacido , Focalización Isoeléctrica , Masculino , LinajeRESUMEN
Cystic kidney diseases are clinically and genetically heterogeneous. The most important entities are autosomal-dominant and autosomal-recessive polycystic kidney diseases. The proteins encoded by the involved genes are referred to as cystoproteins, which are located predominantly in the primary cilia. Primary cilia play an important role in cyst formation. Inherited polycystic kidney diseases belong to the increasing number of reported ciliopathies, including several syndromic entities. An exact diagnosis is the basis for medical care and genetic counselling; thus, the diagnostic algorithm should include clinical, ultrasonographic and morphological features of the underlying kidney disease, knowledge about further features and family history. Molecular genetic testing may contribute important information towards a definite diagnosis.
Asunto(s)
Predisposición Genética a la Enfermedad/genética , Predisposición Genética a la Enfermedad/prevención & control , Pruebas Genéticas/métodos , Enfermedades Renales Quísticas/diagnóstico , Enfermedades Renales Quísticas/genética , Polimorfismo de Nucleótido Simple/genética , Diagnóstico Precoz , HumanosRESUMEN
BACKGROUND: Technical advancement and availability of high-throughput analysis has advanced molecular subtyping of most cancers. Thus, new possibilities for precision oncology have emerged. AIM: Therefore, we aimed to collect data regarding availability and use of next generation sequencing (NGS) for urothelial cancer within the uropathology working group of the German Society of Pathology. METHODS: We collected data by questionnaires and additionally asked for sequencing results of bladder cancers in the participating institutions. RESULTS: A total of 13 university-affiliated institutes of pathology took part in the survey. All university institutes offer NGS-based molecular panel diagnostics and provide panels covering between 15 and 170 genes. Altogether, only 20 bladder cancers were sequenced in routine diagnostics and for 10 cancers potential targeted treatment options were available. DISCUSSION: So far, despite availability of NGS diagnostics at university institutes of pathology, only few bladder cancer samples have been sequenced. Based on current data from the molecular subtyping of bladder cancers, we recommend a step-by-step protocol with basic immunohistochemistry analysis and subsequent subtype-dependent analyses, e.g., alterations of the fibroblast growth factor receptors (FGFR) or comprehensive gene panel analyses.