RESUMEN
Congenital fibrosis of the extraocular muscles type 1 (CFEOM1; OMIM #135700) is an autosomal dominant strabismus disorder associated with defects of the oculomotor nerve. We show that individuals with CFEOM1 harbor heterozygous missense mutations in a kinesin motor protein encoded by KIF21A. We identified six different mutations in 44 of 45 probands. The primary mutational hotspots are in the stalk domain, highlighting an important new role for KIF21A and its stalk in the formation of the oculomotor axis.
Asunto(s)
Variación Genética , Cinesinas/genética , Mutación/genética , Proteínas del Tejido Nervioso/genética , Músculos Oculomotores/patología , Oftalmoplejía/congénito , Secuencia de Aminoácidos , Niño , Femenino , Fibrosis , Ligamiento Genético , Heterocigoto , Humanos , Masculino , Datos de Secuencia Molecular , Oftalmoplejía/patología , Linaje , Fenotipo , Homología de Secuencia de AminoácidoRESUMEN
Rapunzel syndrome is a rare form of tricobezoar with a tail extending from the stomach into the small bowel; surgical removal is generally required. About 60 cases have been reported and described in the literature since 1968. We present the case of an 8-year-old girl who, during the course of a genetic consultation, was initially assigned with a clinical suspicion of ectodermal dysplasia. Surgical intervention, which resulted in the extraction of a tricobezoar of enormous size and extension, led us to the diagnosis of Rapunzel syndrome. The possibility of a tricobezoar should be considered in all cases of adolescent patients who present signs of intestinal occlusion or sub-occlusion, suffer from psychiatric disorders, and have a history of trichotillomania. Endoscopic methodology, medical imaging and clinical diagnostics are fundamental for a differential diagnosis. Psychiatric follow-up is advised to prevent recurrence.
RESUMEN
Wolcott-Rallison syndrome (WRS) is a rare autosomal-recessive disorder characterized by the association of permanent neonatal or early-infancy insulin-dependent diabetes, multiple epiphyseal dysplasia and growth retardation, and other variable multisystemic clinical manifestations. Based on genetic studies of two inbred families, we previously identified the gene responsible for this disorder as EIF2AK3, the pancreatic eukaryotic initiation factor 2alpha (eIF2alpha) kinase. Here, we have studied 12 families with WRS, totalling 18 cases. With the exception of one case, all patients carried EIF2AK3 mutations resulting in truncated or missense versions of the protein. Exclusion of EIF2AK3 mutations in the one patient case was confirmed by both linkage and sequence data. The activities of missense versions of EIF2AK3 were characterized in vivo and in vitro and found to have a complete lack of activity in four mutant proteins and residual kinase activity in one. Remarkably, the onset of diabetes was relatively late (30 months) in the patient expressing the partially defective EIF2AK3 mutant and in the patient with no EIF2AK3 involvement (18 months) compared with other patients (<6 months). The patient with no EIF2AK3 involvement did not have any of the other variable clinical manifestations associated with WRS, which supports the idea that the genetic heterogeneity between this variant form of WRS and EIF2AK3 WRS correlates with some clinical heterogeneity.
Asunto(s)
Diabetes Mellitus Tipo 1/genética , Enanismo/genética , Heterogeneidad Genética , Mutación , Osteocondrodisplasias/genética , eIF-2 Quinasa/genética , Adolescente , Adulto , Niño , Preescolar , Consanguinidad , Genes Recesivos , Humanos , Lactante , Mutación Missense , Linaje , SíndromeRESUMEN
We report two new patients with the Patterson-Lowry rhizomelic dysplasia characterized by very short humeri, coxa vara with proximal femoral epiphyseal involvement, short metacarpals, metatarsals and phalanges. The expression of clinical and radiological characteristics is significantly variable, but the unique proximal metaepiphyseal appearance of humeri makes the syndrome easily identifiable. All the reported patients are sporadic. The genetics of the syndrome remain unclear for the moment.