Recovery of chronic motor neuropathy due to acute intermittent porphyria after givosiran treatment in a young boy: a case report.

BACKGROUND: We describe the first case of a pediatric patient with acute intermittent porphyria and severe chronic porphyric neuropathy treated with givosiran, a small-interfering RNA that drastically decreases delta-aminolevulinic acid production and reduces porphyric attacks' recurrence. CASE REPORT: A 12-year-old male patient with refractory acute intermittent porphyria and severe porphyric neuropathy was followed prospectively for 12 months after givosiran initiation (subcutaneous, 2.5 mg/kg monthly). Serial neurological, structural, and resting-state functional magnetic resonance imaging (MRI) evaluations were performed, including clinical scales and neurophysiological tests. Delta-aminolevulinic acid urinary levels dropped drastically during treatment. In parallel, all the administered neurological rating scales and neurophysiological assessments showed improvement in all domains. Moreover, an improvement in central motor conduction parameters and resting-state functional connectivity in the sensory-motor network was noticed. At the end of the follow-up, the patient could walk unaided after using a wheelchair for 5 years. CONCLUSIONS: A clear beneficial effect of givosiran was demonstrated in our patient with both clinical and peripheral nerve neurophysiologic outcome measures. Moreover, we first reported a potential role of givosiran in recovering central motor network impairment in acute intermittent porphyria (AIP), which was previously unknown. This study provides Class IV evidence that givosiran improves chronic porphyric neuropathy.

Transcranial color Doppler in stroke-free adult patients with sickle cell disease.

The threshold velocity ≥200 cm/s at transcranial Doppler (TCD) evaluation is a useful cut-off for preventing the stroke (STOP trial) in pediatric patients with sickle cell disease (SCD), term including different types of sickle genotypes. Scanty data are available for adult SCD patients. We compared intracranial blood flow velocities between adult SCD patients and controls using transcranial color Doppler (TCCD), measuring the peak of systolic velocity (PSV) with the insonation angle correction and the pulsatility index (PI), an indicator of endothelial elasticity. Fifty-three adult SCD patients (aged >18 years) were enrolled (15 sickle cell anemia, 26 sickle cell thalassemia, and 12 HbS/HbC). None of the patients presented neurological signs. PSVs in middle cerebral artery (MCA) were higher in SCD patients than in controls (p = 0.001). In sickle cell anemia patients, PSVs were higher when compared to HbS/ßThal (p < 0.0060) and HbS/HbC patients (p < 0.0139). PI was within the lower range of normality in SCD patients compared to controls. Moreover, MCA-PSV was higher with lower Hb levels and higher HbS%; PI did not change with variation of Hb levels and HbS%.PSV and PI in SCD adult patients could be a relevant index to indicate the abnormal cerebral blood flow and to detect the sickle endothelial damage, in order to prevent cerebrovascular accidents.

Laboratory diagnosis of thalassemia.

The thalassemias can be defined as α- or ß-thalassemias depending on the defective globin chain and on the underlying molecular defects. The recognition of carriers is possible by hematological tests. Both α- and ß-thalassemia carriers (heterozygotes) present with microcytic hypochromic parameters with or without mild anemia. Red cell indices and morphology followed by separation and measurement of Hb fractions are the basis for identification of carriers. In addition, iron status should be ascertained by ferritin or zinc protoporphyrin measurements and the iron/total iron-binding capacity/saturation index. Mean corpuscular volume and mean corpuscular hemoglobin are markedly reduced (mean corpuscular volume: 60-70 fl; MCH: 19-23 pg) in ß-thalassemia carriers, whereas a slight to relevant reduction is usually observed in α-carriers. HbA2 determination is the most decisive test for ß-carrier detection although it can be disturbed by the presence of δ-thalassemia defects. In α-thalassemia, HbA2 can be lower than normal and it assumes significant value when iron deficiency is excluded. Several algorithms have been introduced to discriminate from thalassemia carriers and subjects with iron-deficient anemia; because the only discriminating parameter is the red cell counts, these formulas must be used consciously. Molecular analysis is not required to confirm the diagnosis of ß-carrier, but it is necessary to confirm the α-thalassemia carrier status. The molecular diagnosis is essential to predict severe transfusion-dependent and intermediate-to-mild non-transfusion-dependent cases. DNA analysis on chorionic villi is the approach for prenatal diagnosis and the methods are the same used for mutations detection, according to the laboratory facilities and expertise.

X-chromosomal inactivation directly influences the phenotypic manifestation of X-linked protoporphyria.

X-linked protoporphyria (XLP), a rare erythropoietic porphyria, results from terminal exon gain-of-function mutations in the ALAS2 gene causing increased ALAS2 activity and markedly increased erythrocyte protoporphyrin levels. Patients present with severe cutaneous photosensitivity and may develop liver dysfunction. XLP was originally reported as X-linked dominant with 100% penetrance in males and females. We characterized 11 heterozygous females from six unrelated XLP families and show markedly varying phenotypic and biochemical heterogeneity, reflecting the degree of X-chromosomal inactivation of the mutant gene. ALAS2 sequencing identified the specific mutation and confirmed heterozygosity among the females. Clinical history, plasma and erythrocyte protoporphyrin levels were determined. Methylation assays of the androgen receptor and zinc-finger MYM type 3 short tandem repeat polymorphisms estimated each heterozygotes X-chromosomal inactivation pattern. Heterozygotes with equal or increased skewing, favoring expression of the wild-type allele had no clinical symptoms and only slightly increased erythrocyte protoporphyrin concentrations and/or frequency of protoporphyrin-containing peripheral blood fluorocytes. When the wild-type allele was preferentially inactivated, heterozygous females manifested the disease phenotype and had both higher erythrocyte protoporphyrin levels and circulating fluorocytes. These findings confirm that the previous dominant classification of XLP is inappropriate and genetically misleading, as the disorder is more appropriately designated XLP.

[Sildenafil assumption and acute effects on the uroflowmetric parameters]. / Assunzione di sildenafil e repida variazione dei parametri uroflussometrici.

AIM: In the recent literature, great attention has been given to the evaluation of the real effectiveness of the phosphodiesterase type 5 inhibitors (PDE-5i), usually prescribed for the erectile dysfunction (ED), in the treatment of the lower urinary tracts symptoms (LUTS). The aim of this study was the evaluation of the acute effects of sildenafil on the uroflowmetric parameters. METHODS: Within September 2011 and February 2012, twenty-seven patients, affected by ED with a IIEF-5 score ≤21 and a contextual IPSS within 8 e 19, have been selected and enrolled in this study. Two uroflowmetric measurements with suprapubic ultrasound valuation of the post voiding residual (PVR) were performed on each patient, 2 hours before and after the administration of sildenafil (50 mg). RESULTS: The average age of the patients came out within di 47.3±9.4 years. On the baseline, the average of the Qmax registered has been 15.6±3.3 mL/s, the average Qave has been 8.2±3.2 mL/s and the average resulted 32.5±11.4 mL. After the mono-administration of sildenafil 50 mg, the average Qmax value, the Qave one and the RPM one turned out into 17.7±5.1 mL/s, 10.1±3.5 mL/s and 22.6±9.6 mL. The differences within the standard values, were considered statistically relevant (P<0.05). CONCLUSIONS: Actually, the study shows that, in the acute phase, the administration of sildenafil 50 mg leads to effects on the uroflowmetric standards on men affected by LUTS and DE.

The geographical and environmental determinants of genetic diversity for four alpine conifers of the European Alps.

Climate is one of the most important drivers of local adaptation in forest tree species. Standing levels of genetic diversity and structure within and among natural populations of forest trees are determined by the interplay between climatic heterogeneity and the balance between selection and gene flow. To investigate this interplay, single nucleotide polymorphisms (SNPs) were genotyped in 24 to 37 populations from four subalpine conifers, Abies alba Mill., Larix decidua Mill., Pinus cembra L. and Pinus mugo Turra, across their natural ranges in the Italian Alps and Apennines. Patterns of population structure were apparent using a Bayesian clustering program, STRUCTURE, which identified three to five genetic groups per species. Geographical correlates with these patterns, however, were only apparent for P. cembra. Multivariate environmental variables [i.e. principal components (PCs)] were subsequently tested for association with SNPs using a Bayesian generalized linear mixed model. The majority of the SNPs, ranging from six in L. decidua to 18 in P. mugo, were associated with PC1, corresponding to winter precipitation and seasonal minimum temperature. In A. alba, four SNPs were associated with PC2, corresponding to the seasonal minimum temperature. Functional annotation of those genes with the orthologs in Arabidopsis revealed several genes involved in abiotic stress response. This study provides a detailed assessment of population structure and its association with environment and geography in four coniferous species in the Italian mountains.

Clinical, biochemical and genetic characteristics of Variegate Porphyria in Italy.

Variegate Porphyria (VP) is an autosomal dominant disorder found worldwide but is rare in Italy. In this study we provide an overview of clinical, biochemical and genetic background of 33 Italian VP patients diagnosed in the last fifteen years. About 70% of patients had experienced clinical symptoms: 43.4% had photosensivity, 8.7% acute attacks and 47.8% both. Among the 33 patients, 14 different mutations were identified. Of these only 6 defects have been previously described in other countries and 8 are unique having been identified for the first time in Italy. Two of these, the c.851G>T and the c.1013C>G, were found in two and four unrelated families respectively. No mutation has been found in homozygosis and no significant correlation has been observed between specific clinical and biochemical manifestations and the type of mutation. In contrast, normal faecal protoporphyrin excretion was high predictive of silent phenotype. Normal urinary excretion of PBG and ALA, predicted absence of neurovisceral symptoms. This paper represents the first compilation of data on genotype-phenotype relation in Italian patients with VP.

Co-existence of two functional mutations on the same allele of the human ferrochelatase gene in erythropoietic protoporphyria.

Erythropoietic protoporphyria (EPP) is an autosomal dominant disease with incomplete penetrance due to reduced activity of ferrochelatase (FECH), a mitochondrial enzyme that catalyzes the final step of the heme biosynthetic pathway. The clinical phenotype of EPP results from co-inheritance of a mutated allele and a wild-type low-expressed allele of the FECH gene. To date, more than 88 different mutations have been identified in the FECH gene of patients with EPP. There are evidences suggesting that an entire haplotype (-251G, IVS1-23T and IVS3-48C) reduces allele expression. In this study, we searched for the -251A/G, IVS1-23C/T and IVS3-48T/C polymorphisms in two unrelated Italian families with EPP. In all the patients, carrying the -250G>C mutation in the promoter region, the IVS3-48C on the other allele showed apparent homozygosity and absence of Mendelian segregation. By RNA and long polymerase chain reaction analysis, we identified a deletion of 5576 bp (g12490_18067), including exons 3 and 4, in cis with the -250G>C mutation in the promoter.