Novel Genetic Microvascular Dysplasia Causing Hypoperfusion of Cardiac, Renal, and Cerebral Circulation.

BACKGROUND: Microvascular disorders represent an uncommon site of tissue hypo-perfusion and damage. Various genetic and acquired causes can be involved. A 65-year-old man was admitted because of refractory angina, which he had had since the age of 30 years, micro-hematuria, and recurrent transitory ischemic attacks from the age of 64. METHODS: Hematochemical studies, ECG, Holter monitoring, 2D-echo, cardiac magnetic resonance (CMR), CTA of cerebral vessels, endomyocardial coronary angiography, and kidney biopsy processes were undertaken. Gene mutation analysis was conducted using next-generation sequencing, which included more than 5000 genes associated with inherited diseases. RESULTS: Hematochemical findings were unremarkable. The ECG, Holter, 2D-echo, and CTA of brain vessels were normal. Cerebral magnetic resonance showed the presence of multiple small foci of ischemia. Coronary and ventricular angiography showed normal arteries with remarkably slow flow and multiple biventricular micro-aneurysms. At the endomyocardial biopsy, five of seven arterioles presented severe lumen obstruction due to hypertrophy and disarray of the muscular coat. Similarly, obstructed pre-glomerular arteries with glomerular sclerosis were seen at the renal biopsy. Genetics identified mutations in the ABCC6, MMP2, and XYLT1 genes, which play pivotal roles in the extracellular matrix. CONCLUSION: This study described a new genetic microvascular obstructive disease causing progressive hypo-perfusion of the human brain, heart, and kidney.

A novel ANO3 variant in two siblings with different phenotypes.

INTRODUCTION: Dystonia type 24 is due to the mutation of the ANO3 gene. It generally consists of craniocervical dystonia associated with tremor; however, other neurological manifestations may also occur. Scientific literature has been expanding on its phenotype over the past few years. CASE: Here we present two siblings affected by dystonia 24 associated to a novel missense mutation of the ANO3 gene. Description of their phenotype, with regard to motor and non-motor features, may improve the knowledge on DYT 24. Consistent with previous reports, our patients presented with cranio-cervical involvement, and they also exhibited different severity and phenotypes. However non-motor symptoms were present too. CONCLUSION: Dystonia 24 spectrum is continuously expanding. This case suggests that the ANO3 missense mutation should be sought in all cases of dystonia and isolated tremor and that non-motor symptoms are an integral part of dystonic syndromes. It also shows that clinical and treatment features may vary from patient to patient, even if they may present the same mutation.

Clinical variability in DYNC2H1-related skeletal ciliopathies includes Ellis-van Creveld syndrome.

Deleterious variants of DYNC2H1 gene are associated with a wide spectrum of skeletal ciliopathies (SC). We used targeted parallel sequencing to analyze 25 molecularly unsolved families with different SCs. Deleterious DYNC2H1 variants were found in six sporadic patients and two monozygotic (MZ) twins. Clinical diagnoses included short rib-polydactyly type 3 in two cases, and asphyxiating thoracic dystrophy (ATD) in one case. Remarkably, clinical diagnosis fitted with EvC, mixed ATD/EvC and short rib-polydactyly/EvC phenotypes in three sporadic patients and the MZ twins. EvC/EvC-like features always occurred in compound heterozygotes sharing a previously unreported splice site change (c.6140-5A>G) or compound heterozygotes for two missense variants. These results expand the DYNC2H1 mutational repertoire and its clinical spectrum, suggesting that EvC may be occasionally caused by DYNC2H1 variants presumably acting as hypomorphic alleles.

A dangerous food binge: a case report of hypokalemic periodic paralysis and review of current literature.

BACKGROUND: Hypokalemic periodic paralysis is a rare neuromuscular genetic disorder due to defect of ion channels and subsequent function impairment. It belongs to a periodic paralyses group including hyperkalemic periodic paralysis (HEKPP), hypokalemic periodic paralysis (HOKPP) and Andersen-Tawil syndrome (ATS). Clinical presentations are mostly characterized by episodes of flaccid generalized weakness with transient hypo- or hyperkalemia. CASE PRESENTATION: A teenage boy presented to Emergency Department (ED) for acute weakness and no story of neurological disease, during the anamnestic interview he revealed that he had a carbohydrates-rich meal the previous evening. Through a focused diagnostic work-up the most frequent and dangerous causes of paralysis were excluded, but low serum potassium concentration and positive family history for periodic paralyses raised the diagnostic suspicion of HOKPP. After the acute management in ED, he was admitted to Pediatric Department where a potassium integration was started and the patient was counselled about avoiding daily life triggers. He was discharged in few days. Unfortunately, he presented again because of a new paralytic attack due to a sugar-rich food binge the previous evening. Again, he was admitted and treated by potassium integration. This time he was strongly made aware of the risks he may face in case of poor adherence to therapy or behavioral rules. Currently, after 15 months, the boy is fine and no new flare-ups are reported. CONCLUSION: HOKPP is a rare disease but symptoms can have a remarkable impact on patients' quality of life and can interfere with employment and educational opportunities. The treatment aims to minimize the paralysis attacks by restoring normal potassium level in order to reduce muscle excitability but it seems clear that a strong education of the patient about identification and avoidance triggering factors is essential to guarantee a benign clinical course. In our work we discuss the typical clinical presentation of these patients focusing on the key points of the diagnosis and on the challenges of therapeutic management especially in adolescence. A brief discussion of the most recent knowledge regarding this clinical condition follows.

Prevalence, Type, and Molecular Spectrum of NF1 Mutations in Patients with Neurofibromatosis Type 1 and Congenital Heart Disease.

The aim of this study was to assess the prevalence and type of congenital heart disease (CHD) and the associated mutation spectrum in a large series of patients with neurofibromatosis type 1 (NF1), and correlate the mutation type with the presence and subgroups of cardiac defects. The study cohort included 493 individuals with molecularly confirmed diagnosis of NF1 for whom cardiac evaluation data were available. CHD was reported in 62/493 (12.6%) patients. Among these patients, 23/62 (37.1%) had pulmonary valve stenosis/dysplasia, 20/62 (32.3%) had mitral valve anomalies, and 10/62 (16.1%) had septal defects. Other defects occurred as rare events. In this NF1 subcohort, three subjects carried a whole-gene deletion, while 59 were heterozygous for an intragenic mutation. A significantly increased prevalence of non-truncating intragenic mutations was either observed in individuals with CHD (22/59, 37.3%) or with pulmonary valve stenosis (13/20, 65.0%), when compared to individuals without CHD (89/420, 21.2%) (p = 0.038) or pulmonary valve stenosis (98/459, 21.4%) (p = 0.002). Similarly, patients with non-truncating NF1 mutations displayed two- and six-fold higher risk of developing CHD (odds ratio = 1.9713, 95% confidence interval (CI): 1.1162-3.4814, p = 0.0193) and pulmonary valve stenosis (odds ratio = 6.8411, 95% CI: 2.6574-17.6114, p = 0.0001), respectively. Noteworthy, all but one patient (19/20, 95.0%) with pulmonary valve stenosis, and 18/35 (51.4%) patients with other CHDs displayed Noonan syndrome (NS)-like features. Present data confirm the significant frequency of CHD in patients with NF1, and provide further evidence for a higher than expected prevalence of NF1 in-frame variants and NS-like characteristics in NF1 patients with CHD, particularly with pulmonary valve stenosis.

Mutational spectrum and clinical signatures in 114 families with hereditary multiple osteochondromas: insights into molecular properties of selected exostosin variants.

Hereditary multiple osteochondromas (HMO) is a rare autosomal dominant skeletal disorder, caused by heterozygous variants in either EXT1 or EXT2, which encode proteins involved in the biogenesis of heparan sulphate. Pathogenesis and genotype-phenotype correlations remain poorly understood. We studied 114 HMO families (158 affected individuals) with causative EXT1 or EXT2 variants identified by Sanger sequencing, or multiplex ligation-dependent probe amplification and qPCR. Eighty-seven disease-causative variants (55 novel and 32 known) were identified including frameshift (42%), nonsense (32%), missense (11%), splicing (10%) variants and genomic rearrangements (5%). Informative clinical features were available for 42 EXT1 and 27 EXT2 subjects. Osteochondromas were more frequent in EXT1 as compared to EXT2 patients. Anatomical distribution of lesions showed significant differences based on causative gene. Microscopy analysis for selected EXT1 and EXT2 variants verified that EXT1 and EXT2 mutants failed to co-localize each other and loss Golgi localization by surrounding the nucleus and/or assuming a diffuse intracellular distribution. In a cell viability study, cells expressing EXT1 and EXT2 mutants proliferated more slowly than cells expressing wild-type proteins. This confirms the physiological relevance of EXT1 and EXT2 Golgi co-localization and the key role of these proteins in the cell cycle. Taken together, our data expand genotype-phenotype correlations, offer further insights in the pathogenesis of HMO and open the path to future therapies.

Novel and recurrent EVC and EVC2 mutations in Ellis-van Creveld syndrome and Weyers acrofacial dyostosis.

Ellis van Creveld syndrome and Weyers acrofacial dysostosis are allelic disorders caused by mutations in EVC or EVC2 genes. We illustrate the results of direct analysis of whole EVC and EVC2 genes' coding regions in 32 unrelated families with clinical diagnosis of Ellis van Creveld syndrome and in 2 families with Weyers acrofacial dysostosis. We identified mutations in 27/32 (84%) cases with Ellis van Creveld syndrome and 2/2 cases with Weyers acrofacial dysostosis. Of the Ellis van Creveld syndrome cases, 20/27 (74%) had a mutation in EVC and 7/27 (26%) in EVC2 genes. The two subjects with Weyers acrofacial dysostosis had a heterozygous mutation in the last exon of EVC2. In total, we detected 25 independent EVC and 11 independent EVC2 mutations. Nineteen EVC mutations (19/25, 76%) and 4 EVC2 mutations (4/11, 36%) were novel. Also one EVC2 gene mutation found in Weyers acrofacial dysostosis was novel. In 5 unrelated cases with a clinical diagnosis of Ellis van Creveld syndrome, we did not find any mutation in either EVC or EVC2 genes. Current findings expand the Ellis van Creveld syndrome and Weyers acrofacial dysostosis mutation spectra, and provide further evidence that the last exon of EVC2 gene is a hot spot for Weyers acrofacial dysostosis mutations. Accordingly, EVC2 exon 22 should be analyzed with priority by mutation screening in individuals with a suspected diagnosis of Weyers acrofacial dysostosis.