RESUMEN
Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) syndrome, caused by mutations in the thymidine phosphorylase gene, manifests as a multisystemic disorder characterized by severe gastrointestinal dysmotility, cachexia, ptosis and ophthalmoparesis, peripheral neuropathy, and leukoencephalopathy. These clinical manifestations, with the exception of leukoencephalopathy, are mimicked by MNGIE-like syndrome, linked to polymerase-gamma (POLG) gene. Here, we report a 49-year-old Chinese man with MNGIE-like syndrome involved leukoencephalopathy and was associated with novel POLG mutations. This case expands the clinical spectrum of MNGIE-like syndrome.
RESUMEN
Parkinsonian features have been described in patients with POLG1 mutations. Notwithstanding, the clinical expression has been revealed heterogeneous and the response to dopaminergic treatment has been document in few cases. We aim to describe the longitudinal clinical features and the treatment response of three unrelated patients with neurodegenerative parkinsonism, preceded by PEO and SANDO syndromes, who harbor POLG1 mutations, including two novel mutations. It was documented a sustained response to levodopa, at 3 and 8 years of follow-up of parkinsonian syndrome, and reduced striatal dopamine uptake. We review the genotypic and phenotypic spectrum of POLG1-related parkinsonism. Our observations stimulate the debate around the role of mitochondrial DNA defects in the pathogenesis of neurodegenerative parkinsonism.
Asunto(s)
Antiparkinsonianos/farmacología , ADN Polimerasa Dirigida por ADN/genética , Levodopa/farmacología , Trastornos Parkinsonianos/tratamiento farmacológico , Trastornos Parkinsonianos/genética , Anciano , Antiparkinsonianos/administración & dosificación , ADN Polimerasa gamma , ADN Mitocondrial/genética , Femenino , Genotipo , Humanos , Levodopa/administración & dosificación , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Fenotipo , Resultado del TratamientoRESUMEN
Chromosomal microarray analysis is now commonly used in clinical practice to identify copy number variants (CNVs) in the human genome. We report our experience with the use of the 105 K and 180K oligonucleotide microarrays in 215 consecutive patients referred with either autism or autism spectrum disorders (ASD) or developmental delay/learning disability for genetic services at the University of Kansas Medical Center during the past 4 years (2009-2012). Of the 215 patients [140 males and 75 females (male/female ratio=1.87); 65 with ASD and 150 with learning disability], abnormal microarray results were seen in 45 individuals (21%) with a total of 49 CNVs. Of these findings, 32 represented a known diagnostic CNV contributing to the clinical presentation and 17 represented non-diagnostic CNVs (variants of unknown significance). Thirteen patients with ASD had a total of 14 CNVs, 6 CNVs recognized as diagnostic and 8 as non-diagnostic. The most common chromosome involved in the ASD group was chromosome 15. For those with a learning disability, 32 patients had a total of 35 CNVs. Twenty-six of the 35 CNVs were classified as a known diagnostic CNV, usually a deletion (n=20). Nine CNVs were classified as an unknown non-diagnostic CNV, usually a duplication (n=8). For the learning disability subgroup, chromosomes 2 and 22 were most involved. Thirteen out of 65 patients (20%) with ASD had a CNV compared with 32 out of 150 patients (21%) with a learning disability. The frequency of chromosomal microarray abnormalities compared by subject group or gender was not statistically different. A higher percentage of individuals with a learning disability had clinical findings of seizures, dysmorphic features and microcephaly, but not statistically significant. While both groups contained more males than females, a significantly higher percentage of males were present in the ASD group.