RESUMEN
CONTEXT: Primary ovarian insufficiency (POI) is a cause of female infertility. However, the genetic etiology of this disorder remains unknown in most patients with POI. OBJECTIVE: To investigate the genetic etiology of idiopathic POI. PATIENTS AND METHODS: We performed whole-exome sequencing of 11 families with idiopathic POI. To gain insights into the potential mechanisms associated with this mutation, we generated two mouse lines via clustered regularly interspaced short palindromic repeats/Cas9 technology. RESULTS: A pathogenic homozygous missense mutation (c.149A>G; p.Asp50Gly) in the POLR3H gene in two unrelated families was identified. Pathogenic mutations in this subunit have not been associated with human disorders. Loss-of-function Polr3h mutation in mice caused early embryonic lethality. Mice with homozygous point mutation (Polr3hD50G) were viable but showed delayed pubertal development, characterized by late first estrus or preputial separation. The Polr3hD50G female and male mice showed decreased fertility later in life, associated with small litter size and increased time to pregnancy or to impregnate a female. Polr3hD50G mice displayed decreased expression of ovarian Foxo3a and lower numbers of primary follicles. CONCLUSION: Our manuscript provides a case of POI caused by missense mutation in POLR3H, expanding the knowledge of molecular pathways of the ovarian function and human infertility. Screening of the POLR3H gene may elucidate POI cases without previously identified genetic causes, supporting approaches of genetic counseling.
Asunto(s)
Insuficiencia Ovárica Primaria/genética , ARN Polimerasa III/genética , Adolescente , Animales , Sistemas CRISPR-Cas , Niño , Femenino , Proteína Forkhead Box O3/metabolismo , Técnicas de Inactivación de Genes , Heterocigoto , Homocigoto , Humanos , Infertilidad/genética , Tamaño de la Camada , Mutación con Pérdida de Función , Masculino , Ratones , Mutación Missense , Ovario/metabolismo , Maduración Sexual/genética , Tiempo para Quedar Embarazada , Secuenciación del ExomaRESUMEN
PURPOSE: Primary ovarian failure (POF) is characterized by amenorrhea, hypoestrogenism, and elevated gonadotropin levels in women leading to infertility under the age of 40 years. POF is a heterogeneous disease with different causes, and several genes have been associated with the POF phenotype. Thus, Whole-exome sequencing (WES) was performed in a consanguineous family with two sisters affected by POF. METHODS: All exons of both sisters were massively sequenced by WES, and the segregation was confirmed by Sanger sequencing. RESULTS: The novel homozygous c.1489delT variant in the NOBOX gene was identified in the two sisters with POF. Their parents were heterozygous carriers of this variant and, therefore, consistent with an autosomal recessive mode of inheritance. The c.1489delT NOBOX variant has not been previously reported in any public available databases (1000Genomes, 6500ESP/EVS, ExAC, and gnomAD). Furthermore, this variant was neither present in 387 Brazilian exomes control individuals nor in 200 fertile Brazilian women screened by Sanger sequencing. CONCLUSION: We report the first familial case of a novel homozygous NOBOX variant with an autosomal recessive mode of inheritance, thus allowing for a genetic diagnosis of primary ovarian failure.
Asunto(s)
Proteínas de Homeodominio/genética , Insuficiencia Ovárica Primaria/genética , Factores de Transcripción/genética , Adolescente , ADN/genética , Femenino , Eliminación de Gen , Genes Recesivos , Pruebas Genéticas , Genoma , Gonadotropinas/sangre , Homocigoto , Hormonas/sangre , Humanos , Linaje , Análisis de Secuencia de ADN , Hermanos , Adulto JovenRESUMEN
AIMS: To determine the presence of abnormal body proportion, assessed by sitting height/height ratio for age and sex (SH/H SDS) in healthy and short individuals, and to estimate its role in selecting short children for SHOX analysis. METHODS: Height, sitting height and weight were evaluated in 1,771 healthy children, 128 children with idiopathic short stature (ISS), 58 individuals with SHOX defects (SHOX-D) and 193 females with Turner syndrome (TS). RESULTS: The frequency of abnormal body proportion, defined as SH/H SDS >2, in ISS children was 16.4% (95% CI 10-22%), which was higher than in controls (1.4%, 95% CI 0.8-1.9%, p < 0.001). The SHOX gene was evaluated in all disproportionate ISS children and defects in this gene were observed in 19%. Among patients with SHOX-D, 88% of children (95% CI 75-100%) and 96% of adults had body disproportion. In contrast, SH/H SDS >2 were less common in children (48%, 95% CI 37-59%) and in adults (28%, 95% CI 20-36%) with TS. CONCLUSION: Abnormal body proportions were observed in almost all individuals with SHOX-D, 50% of females with TS and 16% of children considered ISS. Defects in SHOX gene were identified in 19% of ISS children with SH/H SDS >2, suggesting that SH/H SDS is a useful tool to select children for undergoing SHOX molecular studies.
Asunto(s)
Estatura , Análisis Mutacional de ADN , Trastornos del Crecimiento/diagnóstico , Trastornos del Crecimiento/genética , Proteínas de Homeodominio/genética , Postura , Adolescente , Adulto , Factores de Edad , Niño , Desarrollo Infantil , Estudios Transversales , Femenino , Humanos , Masculino , Selección de Paciente , Fenotipo , Proteína de la Caja Homeótica de Baja Estatura , Síndrome de Turner/genéticaRESUMEN
Descrevemos o caso de uma paciente jovem, portadora de hipertireoidismo por doença de Graves, que durante admissão hospitalar desenvolveu quadro grave de instabilidade hemodinâmica evoluindo com bloqueio atrioventricular total (BAVT) e necessidade de marcapasso provisório. Após introdução de droga antitireoidiana e uso de corticóide, houve recuperação do grau de bloqueio com 36 horas. Um possível mecanismo, no estado de hipertireoidismo, seria o efeito direto do hormônio tireoidiano no sistema de condução ou a infiltração linfocitária na região do sistema de condução cardíaco, considerando a natureza auto-imune da doença de base. Esses mecanismos são discutidos por nós e por outros autores na literatura.