RESUMEN
Clinically manifesting carriers of Duchenne muscular dystrophy (DMD) are rare among the pediatric population. A standardized diagnostic procedure in supposed DMD carriers entails performing a Multiplex Ligation-dependent Probe Amplification analysis of the DMD gene first, then taking a muscle biopsy to confirm reduced dystrophin levels and/or finally a complete sequencing of the DMD gene. We describe a girl with high-elevated creatine kinase, myalgia, and cardiomyopathy. Muscle biopsy showed a dystrophic pattern and nearly absent expression of dystrophin. Diagnosis could not be confirmed by molecular genetic procedures. Because of a mild mental retardation, a chromosome analysis and molecular karyotyping were performed, revealing a balanced translocation t(X;4)(p21;q31).arr(1-22,X)x2 dn with breakpoint on the X-chromosome within an intron of the DMD gene. The inactivation of the nonderivative X-chromosome was found to be in a nonrandom pattern, resulting in a functionally balanced karyotype and thus leading to a manifesting DMD carrier in this case. Chromosome analysis should be recommended in cases of genetically unsolved DMD carriers as a part of the standard genetic procedures.
Asunto(s)
Cromosomas Humanos X/genética , Distrofia Muscular de Duchenne/genética , Translocación Genética/genética , Preescolar , Femenino , Humanos , Cariotipificación , Imagen por Resonancia Magnética , Distrofia Muscular de Duchenne/diagnósticoRESUMEN
Juvenile myasthenia gravis (JMG) is an autoimmune disorder of neuromuscular transmission caused by production of antibodies against components of the postsynaptic membrane of the neuromuscular junction. Ethnicity has influence on incidence, clinical presentation, and the course of the disease. The patients present with a wide range of symptoms-from isolated intermittent ocular symptoms to general muscle weakness with or without respiratory insufficiency. Compared with adults and adolescents, the clinical signs and course of disease in children exhibit differences and occasionally untypical symptoms. Therefore, JMG is often missed and the diagnosis delayed. Isolated ocular symptoms are frequent at onset, spontaneous remission or intermittent symptoms over the longer period of time can occur. Very young children may present with generalized muscle weakness already during the second year of life and in this patient group, specific antibodies can only be slightly increased or even negative. Existing therapeutic options include immunosuppressive therapy and thymectomy but potential long-term side effects on the growing organism and possible influence on immune response in very young children should be considered. Specific clinical symptoms, diagnostic procedures, and a therapeutic approach with consideration of this age group's specificities are discussed.
Asunto(s)
Miastenia Gravis/diagnóstico , Miastenia Gravis/terapia , Adolescente , Adulto , Niño , Preescolar , Humanos , Lactante , Recién Nacido , Adulto JovenRESUMEN
Sepiapterin reductase (SR) deficiency was recently described in patients with a severe biogenic amine deficiency presenting without hyperphenylalaninemia and it was suggested that the tetrahydrobiopterin (BH(4)) pathway may be different in different cells and tissues. We now developed a HPLC method for the measurement of yellow fluorescing sepiapterin for the rapid diagnosis of SR deficiency. Sepiapterin was elevated in CSF from two patients with SR deficiency (5.6 and 11.4 nmol/L) when compared with healthy controls (<0.5 nmol/L). Our data further support the hypothesis that sepiapterin is an intermediate in the salvage pathway of BH(4) and that it accumulates in the brain of patients with SR deficiency.