Adult-onset methylenetetrahydrofolate reductase deficiency.

Severe hyperhomocysteinemia (>100 µmol/L) is often associated with inborn errors of homocysteine metabolism. It manifests typically in neonatal period with developmental delay, hypotonia, feeding problems or failure to thrive. Adult-onset forms are rare and include less severe manifestations. Early diagnosis is crucial because effective treatment is available. A 23-year-old man presented with a 3-week history of speech and gait impairment, and numbness in lower limbs. Neurological examination revealed dysarthria, decreased vibratory sensation in both legs and appendicular and gait ataxia. Brain MRI revealed T2-hyperintense symmetric white matter lesions and cortical atrophy. He had folate and vitamin B12 deficiency, a markedly elevated serum homocysteine and low methionine. Despite vitamin supplementation homocysteine levels remained elevated. Molecular studies of 5,10-methylenetetrahydrofolate reductase (MTHFR) gene revealed a new pathogenic mutation (c.1003C>T (p.Arg335Cys)) and a polymorphism (C677T (p.Ala222Val)) associated with hyperhomocysteinemia, both in homozygosity. The patient started betaine with clinical and biochemical improvement.

Woodhouse-Sakati Syndrome: First report of a Portuguese case.

Woodhouse-Sakati Syndrome is a very rare autosomal recessive disorder caused by pathogenic variants in the DCAF17 gene, which encodes DDB1- and CUL4-associated factor 17. It is a multisystemic disorder characterized by hypogonadism, adolescent- to young adult-onset diabetes mellitus, hypothyroidism, and alopecia. Neurologic involvement includes childhood-onset moderate bilateral sensorineural hearing loss, mild intellectual disability adolescent- to young adult-onset of extrapyramidal findings, dysarthria, and dysphagia. Brain imaging typically reveals iron deposition in the globus pallidus and periventricular leukodystrophy. We report the case of a 31-year-old Portuguese female, the only child of a consanguineous couple. She presented with cognitive impairment, spastic paraparesis, lower limb dystonia, dysarthria, and dysphagia. She also had hypergonadotrophic hypogonadism associated with primary amenorrhea, insulin-dependent diabetes mellitus with retinopathy, primary hypothyroidism, moderate bilateral sensorineural hearing loss, and alopecia. Serial brain magnetic resonance imaging showed a progressive periventricular leukodystrophy with pontine involvement and significant bilateral iron deposition in the globus pallidus, substantia nigra, and red nucleus. The diagnosis of Woodhouse-Sakati Syndrome was eventually proposed and DCAF17 gene sequencing identified a novel likely pathogenic homozygous variant NG_013038.1(NM_025000.3):c.1091+2T>C. Genetic testing allowed a more accurate prognosis and a precise genetic counseling for our patient's family.

Hypocomplementemic urticarial vasculitis and multiple Sclerosis: A rare association or an atypical presentation?

BACKGROUND: Multiple Sclerosis (MS) has been associated with several immune-mediated diseases but the mechanisms that explain such associations, as well as their implications in clinical practice and treatment are rarely discussed. CASE PRESENTATION: We report the case of a patient with a history of MS since she was 27 years old, followed by a diagnosis of Hypocomplementemic Urticarial Vasculitis (HUV) seven years later. Several disease-modifying treatments for MS and HUV were used but with limited benefit in both diseases and significant MS progression. Activity of both diseases was later stabilized with Rituximab. We discuss the hypotheses of a central nervous system involvement in urticarial vasculitis or an association between MS and HUV, and examine the challenges in their management. CONCLUSIONS: In the presence of concurrent immune-mediated diseases, the diagnosis of MS can be challenging. This clinical presentation posed significant difficulties in disease management, influencing therapeutic options and their effectiveness/adverse effects profile. The best approach in MS patients with concurrent autoimmune diseases remains to be established and more reports are needed to help clarify this subject.

Demyelinating disease of the central nervous system associated with Pembrolizumab treatment for metastatic melanoma.

Immune checkpoint inhibitors are used in metastatic melanoma with good efficacy and safety profile. We report the first case of an inflammatory demyelinating disease of the central nervous system during treatment with Pembrolizumab and discuss the evidence in the literature supporting its causative role. The patient had a good clinical recovery after intravenous steroids, plasma exchange and discontinuation of Pembrolizumab. Due to the expected increase in the importance of immune checkpoint inhibitors in cancer treatment, it is important to be aware of neurological adverse events, as early treatment usually leads to good clinical responses.

In silico analysis for predicting pathogenicity of five unclassified mitochondrial DNA mutations associated with mitochondrial cytopathies' phenotypes.

Mitochondrial DNA (mtDNA) mutations have been assigned as a major cause of genetic disease. When a novel sequence variation is found, it is necessary to evaluate its functional impact, usually requiring functional molecular studies. Given the fact that this approach is difficult to put in practice in a routine basis, it is possible to take advantage of the in silico tools available and predict protein/RNA structure changes and therefore pathogenicity. Here, we describe the characterization of five undescribed mtDNA variants, upon detection of 23 unclassified alterations at Laboratory of Biochemical Genetics, from 2004 to 2014. Those five sequence variations are located in protein-coding genes, in five patients with a diverse range of mitochondrial respiratory chain disease phenotypes including encephalopathy, optic neuropathy, developmental delay, deafness and epilepsy. According to the prediction established by in silico analysis using tools to predict structure and function changes (ClustalW2®, PolyPhen-2®, SIFT®, MutationAssessor®, PredictProtein®, Provean®, I-TASSER®, Haplogrep®), from the 23 variants analyzed, the five described are potentially pathogenic. This approach is inexpensive and compatible with a rapid first line response to clinical demanding, contributing to a more rationale genetic diagnosis concerning novel mutations and to clarify the mtDNA involvement in these pathologies.

Severe post-influenza (H1N1) encephalitis involving pulvinar nuclei in an adult patient.

Neurological complications of H1N1 infections are mostly found in children, but rare cases of acute encephalopathy and post-infectious encephalitis such as acute disseminated encephalomyelitis (ADEM) have been described in adults. We report a case of an adult presenting with a progressive and severe encephalopathy that developed after H1N1 respiratory infection resolution. Cerebrospinal fluid (CSF) analysis was normal, including negative PCR for herpes simplex virus, H1N1, influenza B and JC virus, and absent oligoclonal IgG bands in CSF and serum. Initial CT scan was normal, but later MRI showed posterior multifocal leucoencephalopathy with pulvinar sign. The delayed neurological findings together with the ancillary investigation, namely the MRI pattern with both grey and white matter involvement, raised the possibility of a post-infectious process, rather than an acute encephalitis. Despite aggressive immunotherapy, the patient experienced severe neurological sequelae. Early recognition of ADEM manifestations by those dealing with H1N1 infection is important as early immunotherapy may improve the prognosis.

Adolescent-onset Krabbe disease with an initial diagnosis of multiple sclerosis and a novel mutation.

Krabbe disease is a rare autosomal recessive leucodystrophy, with <5% of the cases having an adolescent-onset form. A 30-year-old woman with a history of a subacute episode of gait impairment at 14 years of age, and mild spastic paraparesis since then, was followed with an initial diagnosis of multiple sclerosis. After 10 years of slow disease progression without response to treatment, the initial diagnosis was reviewed, and an extensive metabolic work up revealed decreased activity of galactocerebrosidase. Genetic testing of the GALC gene proved the diagnosis of Krabbe disease and found a novel mutation. This case highlights the value of a critical eye in the initial differential diagnosis, mainly in the presence of atypical findings.

Relative frequency of known causes of multiple mtDNA deletions: two novel POLG mutations.

Diseases affecting mtDNA stability, termed nuclear-mitochondrial intergenomic communication disorders, are caused by a primary nuclear gene defect resulting in multiple mtDNA deletions. The aim of this study was to estimate the frequency of known etiologies and the spectrum of mutations in a cohort of 21 patients harboring multiple mtDNA deletions in skeletal muscle. We showed that 10 cases (48%) display mutations in POLG, including eight previously reported variants and two novel mutations (namely, p.Trp585X and p.Arg1081Gln). The novel mutations affect evolutionary conserved residues and were absent in a large set of control chromosomes. These findings expand the array of mutations associated with multiple rearranged mtDNA attributed to mutations in POLG. The relatively high diagnostic yield (about one in two cases) supports the notion that it is recommended to test POLG routinely in diagnostic laboratories whenever multiple mtDNA deletions are present, regardless of the age of onset of patients and their clinical phenotype.

Evaluation of treatment with cysteamine eyedrops for cystinosis with confocal microscopy.

PURPOSE: The purpose of this study was to evaluate the efficacy of cysteamine eyedrops 0.1136% (new formulation, now stable at room temperature without the need for refrigeration for up to 2 months) for the treatment of cystine crystals in the cornea using slit lamp biomicroscopy and confocal microscopy. METHODS: A 20-year-old woman with infantile cystinosis, with a history of kidney transplantation at age 10, was studied. She applied cysteamine eyedrops (0.1136%) 10 times a day (a new formulation, now stable at room temperature without the need for refrigeration for up to 2 months, was prepared for compassionate use). The density of the cystine crystals in the cornea was evaluated using slit lamp biomicroscopy and confocal microscopy (Heidelberg Retina Tomograph 2 equipped with the Rostock Module for the Cornea). RESULTS: The deposits were absent in the surface epithelium and basal cells of the central cornea before and after treatment. We found crystals mainly in the anterior and medium stroma; they had various shapes; were intracellular, rectangular, or fusiform; and showed hyperreflectivity. The posterior stroma showed lower density of the crystals. No deposits in the endothelium were found. Therapy with cysteamine eyedrops reduced the density of the crystals and lessened the photophobia. CONCLUSION: Confocal microscopy is a valuable technique to study cystine crystals of the cornea in vivo. Cysteamine eyedrops appear to be very useful in the treatment of these crystals, especially for photophobic complaints.