RESUMO
De novo rare damaging variants in genes involved in critical developmental pathways, notably regulation of synaptic transmission, have emerged as a frequent cause of neurodevelopmental disorders (NDD). NDD show great locus heterogeneity and for many of the associated genes, there is substantial phenotypic diversity, including epilepsy, intellectual disability, autism spectrum disorder, movement disorders, and combinations thereof. We report two unrelated patients, a young girl with early-onset refractory epilepsy, severe disability, and progressive cerebral and cerebellar atrophy, and a second girl with mild dysmorphism, global developmental delay, and moderate intellectual disability in whom trio-based whole-exome sequencing analysis uncovered de novo missense variants in CHRM1. Biochemical analyses of one of the NDD-associated variants proved that it caused a reduction in protein levels and impaired cellular trafficking. In addition, the mutated receptor showed defective activation of intracellular signaling pathways. Our data strengthen the concept that brain-reduced muscarinic signaling lowers the seizure threshold and severely impairs neurodevelopment.
Assuntos
Transtorno do Espectro Autista , Epilepsia , Deficiência Intelectual , Transtornos do Neurodesenvolvimento , Epilepsia/genética , Feminino , Humanos , Deficiência Intelectual/genética , Mutação , Transtornos do Neurodesenvolvimento/genética , Receptor Muscarínico M1/genética , Receptores Muscarínicos/genéticaRESUMO
Most apparent balanced chromosomal inversions are usually clinically asymptomatic; however, infertility, miscarriages, and mental retardation have been reported in inversion carriers. We present a small family with a paracentric inversion 1q42.13q43 detected in routine prenatal diagnosis. Molecular cytogenetic methods defined the size of the inversion as 11.7 Mb and excluded other unbalanced chromosomal alterations in the patients. Our findings suggest that intellectual disability is caused by dysfunction, disruption, or position effects of genes located at or near the breakpoints involved in this inversion.
Assuntos
Inversão Cromossômica , Cromossomos Humanos Par 1/genética , Doenças Fetais/genética , Deficiência Intelectual/genética , Diagnóstico Pré-Natal , Pré-Escolar , Bandeamento Cromossômico , Feminino , Doenças Fetais/diagnóstico , Humanos , Hibridização in Situ Fluorescente , Recém-Nascido , Deficiência Intelectual/diagnóstico , GravidezRESUMO
El síndrome de insensibilidad a los andrógenos se caracteriza por la presencia de cariotipo 46,XY, fenotipo femenino y presencia de gónadas masculinas. Es la tercera causa más frecuente de amenorrea primaria, tras la disgenesia gonadal y la ausencia congénita de vagina (síndrome de Mayer-Rokitansky-Küster-Hauser). Se trata de una entidad de interés por su relevancia en la identificación sexual y por su posible asociación con tumores malignos de las gónadas masculinas, que hace necesario un correcto diagnóstico y tratamiento quirúrgico. En este artículo se describen dos casos de síndrome de insensibilidad a los andrógenos, con su estudio clínico-genético y tratamiento, así como su seguimiento (AU)
Androgen insensitivity syndrome is characterized by the presence of external female phenotype, 46,XY karyotype and intraabdominal testes. This syndrome is the third most frequent cause of primary amenorrhea, after gonadal dysgenesis and congenital absence of the vagina (Mayer-Rokitansky-Küster-Hauser syndrome). Androgen insensitivity syndrome is of interest due to its role in sexual identification and its possible association with malignant tumors of the male gonads, which require an accurate diagnosis and surgical treatment. We present two cases of androgen insensitivity syndrome. The results of the clinical and genetic examinations, as well as the treatment and follow-up of these two patients, are discussed (AU)
