Paola Carrera

A new CACNA1A gene mutation in acetazolamide-responsive familial hemiplegic migraine and ataxia

Objective: To search for mutations in the calcium channel gene CACNA1A and to study the genotype–phenotype correlation in a family with a severe familial hemiplegic migraine (FHM) phenotype and a slowly progressive cerebellar ataxia. Background: CACNA1A gene mutations on chromosome 19 are involved in approximately 50% of FHM families. The association of FHM and cerebellar ataxia has been reported in a small number of FHM families, all linked to chromosome 19. Methods: The proband, in addition to typical hemiplegic migraine attacks, experienced severe episodes during which hemiplegia was associated with acutely altered consciousness and fever lasting several days. She, as well as her affected sister, developed a permanent, late-onset cerebellar ataxia and cerebellar atrophy evident on MRI. Linkage analysis was performed and the whole CACNA1A gene, 47 exon–intron boundaries, was analyzed by double gradient–denaturing gradient gel electrophoresis (DG-DGGE). Results: Genetic studies suggested linkage to chromosome 19p13, and DG-DGGE analysis detected a heteroduplex fragment in exon 13 of the CACNA1A gene. By direct sequencing, a G-to-A substitution resulting in an arginine to glutamine change at codon 583 in the second putative voltage sensor domain of the channel α1A-subunit, was identified, possibly representing the disease-causing mutation. The proband and her affected sister were treated with acetazolamide, reporting freedom from new FHM attacks but no benefit in the progression of ataxia. Conclusions: The combination of episodic dysfunction and permanent deficit could depend on the variety of functions of calcium channels and their distribution in the nervous system.

Genetic heterogeneity in Italian families with familial hemiplegic migraine

Objective: To verify linkage to chromosome 19p13, to detect mutations in the CACNA1A gene, and to correlate genetic results to their clinical phenotypes in Italian families with familial hemiplegic migraine (FHM). Background: FHM is an autosomal dominant disease, classified as a subtype of migraine with aura. Only a proportion of FHM patients have been associated with chromosome 19p13. Among these, four missense mutations within the CACNA1A gene in five unrelated families have been described. Methods: A linkage study was performed in 19 patients affected by FHM from five families by studying microsatellite markers associated with the 19p13 region. All familial and seven additional sporadic patients with FHM were analyzed to search for mutations within the CACNA1A gene by applying the double gradient–denaturant gradient electrophoresis technique. Results: Lod score values did not establish significantly linkage to chromosome 19. However, seven new genetic variants were detected: six were new polymorphisms. The seventh was a missense mutation present in family 1, and it was associated with a hemiplegic migraine phenotype without unconsciousness and cerebellar ataxia. Because this missense mutation is absent in the general population and cosegregates with the disease, it may be a pathologic mutation. Conclusions: Genetic heterogeneity of FHM has been shown in familial and sporadic FHM patients of Italian origin. The new missense mutation—G4644T—is associated with milder clinical features compared with typical FHM.

Phenotypic clustering of lamin A/C mutations in neuromuscular patients

Background: Mutations in the LMNA gene, encoding human lamin A/C, have been associated with an increasing number of disorders often involving skeletal and cardiac muscle, but no clear genotype/phenotype correlation could be established to date. Methods: We analyzed the LMNA gene in a large cohort of patients mainly affected by neuromuscular or cardiac disease and clustered mutated patients in two groups to unravel possible correlations. Results: We identified 28 variants, 9 of which reported for the first time. The two groups of patients were characterized by clinical and genetic differences: 1) patients with childhood onset displayed skeletal muscle involvement with predominant scapuloperoneal and facial weakness associated with missense mutations; 2) patients with adult onset mainly showed cardiac disorders or myopathy with limb girdle distribution, often associated with frameshift mutations presumably leading to a truncated protein. Conclusions: Our findings, supported by meta-analysis of previous literature, suggest the presence of two different pathogenetic mechanisms: late onset phenotypes may arise through loss of function secondary to haploinsufficiency, while dominant negative or toxic gain of function mechanisms may explain the severity of early phenotypes. This model of patient stratification may help patient management and facilitate future studies aimed at deciphering lamin A/C pathogenesis.

SOD1 mutations in amyotrophic lateral sclerosis. Results from a multicenter Italian study.

AbstractAmyotrophic Lateral Sclerosis (ALS), the most common form among motoneuron diseases, is characterized by a progressive neurodegenerative process involving motor neurons in the motor cortex, brain stem and spinal cord. Sporadic (SALS) accounts for the majority of patients but in about 10% of ALS cases the disease is inherited (FALS), usually as an autosomal dominant trait.In the present study we show the results of a referred based multicenter study on the distribution of SOD1 gene mutations in the largest cohort of Italian ALS patients described so far. Two hundred and sixty–four patients (39 FALS and 225 SALS) of Italian origin were studied. In 7 out of 39 FALS patients we found the following SOD1 gene mutations: i) a new G12R missense mutation in exon 1, found in a patient with a slowly progressive disease course; ii) the G41S mutation, in four unrelated patients with rapidly progressive course complicated with cognitive decline in two of them; iii) the L114F mutation, in a patient with a slowly progressive phenotype; iv) the D90A mutation, in a heterozygous patient with atypical phenotype. In addition, in one SALS patient a previously reported synonymous variant S59S was identified. In 17 (3 FALS and 14 SALS) out of 264 patients (6.4 %) the polymorphism A→C at position 34 of intron 3 (IVS3: + 34 A→C) was found, and in one FALS patient a novel variant IVS3 + 62 T→C was identified.The frequency of SOD1 gene mutations (17.9 %) in FALS cases was comparable with that found in other surveys with a similar sample size of ALS cases. No SOD1 gene mutations have been identified in SALS cases. Within FALS cases, The most frequent mutation was the G41S identified in four FALS.

Point mutations in Italian patients with classic, non-classic, and cryptic forms of steroid 21-hydroxylase deficiency

Abstract Seventy-three Italian patients affected by steroid 21-hydroxylase deficiency were studied by a PCR –allele-specific oligonucleotide protocol in order to evaluate the presence of eight known point mutations. The majority of chromosomes were found to carry point gene conversions normally present in the pseudogene. Within the classic form, the most common mutations were the splicing mutation A/C-655 to G in intron 2 (34.2%), the nonsense mutation C-1993 to T in exon 8 (10.8%), and the missense mutation T-999 to A in exon 4 (10%). Within the non-classic form, the missense mutation G-1683 to T was the most common (57.7%). Other mutations were either absent, such as the three clustered missense mutations T-1380, T-1383, T-1389 to A in exon 6, or very rare, like the 1761 + T in exon 7 and the C-2108 to T in exon 8. Family genotyping revealed the presence of ten asymptomatic parents carrying mutations in both chromosomes, thus identifying the gene defect in cryptic subjects. Interestingly, the same mutations were found in both symptomatic and asymptomatic forms.

Dominant LMNA mutations can cause combined muscular dystrophy and peripheral neuropathy

The coexistence of neurogenic and myogenic features in scapuloperoneal syndrome is rarely ascribed to a single gene. Defects in the nuclear envelope protein lamin A/C, encoded by the LMNA gene, have been shown to be associated with a variety of disorders affecting mainly the muscular and adipose tissues and, more recently, with autosomal recessive Charcot–Marie–Tooth type 2 neuropathy. This report is about a patient presenting features of myopathy and neuropathy due to a dominant LMNA mutation, suggesting that the peripheral nerve might be affected in primary LMNA myopathy. Our observations further support the marked intrafamilial and interfamilial phenotypic heterogeneity associated with lamin A/C defects.

Efficacy of Low-Dose Intermittent Subcutaneous Interleukin (IL)–2 in Antiviral Drug–Experienced Human Immunodeficiency Virus–Infected Persons with Detectable Virus Load: A Controlled Study of 3 IL-2 Regimens with Antiviral Drug Therapy

To evaluate the safety and efficacy of 3 regimens of intermittent subcutaneous (sc) interleukin (IL)--2 in a phase 2 study, 61 antiviral drug-experienced human immunodeficiency virus (HIV)--positive patients were randomly assigned to one of the following study arms: antiretroviral therapy (ART) plus IL-2 (12 million IU [MIU] by continuous intravenous infusion, followed by 7.5 MIU twice a day, sc, every 8 weeks); ART plus IL-2 (7.5 MIU twice a day, sc, every 8 weeks); ART plus IL-2 (3 MIU twice a day, sc, every 4 weeks); or ART alone. A significant increase of circulating CD4 cells was observed in IL-2--treated subjects, compared with those given ART alone. Low doses of IL-2 were better tolerated. Despite the incomplete suppression of viral replication, IL-2 with ART did not increase either plasma viremia or cell-associated HIV DNA levels. Low doses of intermittent sc IL-2 induced a stable increase of peripheral CD4 cells that was indistinguishable from those associated with higher, less well-tolerated doses of IL-2.

Capturing all disease-causing mutations for clinical and research use: Toward an effortless system for the Human Variome Project

Abstract: The collection of genetic variants that cause inherited disease (causative mutation) has occurred for decades albeit in an ad hoc way, for research and clinical purposes. More recently, the access to collections of mutations causing specific diseases has become essential for appropriate genetic health care. Because information has accumulated, it has become apparent that there are many gaps in our ability to correctly annotate all the changes that are being identified at ever increasing rates. The Human Variome Project (www.humanvariomeproject.org) was initiated to facilitate integrated and systematic collection and access to this data. This manuscript discusses how collection of such data may be facilitated through new software and strategies in the clinical genetics and diagnostic laboratory communities.

Migraine with aura and white matter abnormalities: Notch3 mutation

Article abstract The authors report on an Italian family with eight affected members who show autosomal dominant migraine with prolonged visual, sensory, motor, and aphasic aura. These symptoms are associated with white matter abnormalities on brain MRI. All living affected members carry a Notch3 mutation (Arg153Cys) previously reported in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). White matter abnormalities occur in a variable percentage of the general migraine population; CADASIL should be suspected in migraineurs with prolonged atypical aura and white matter abnormalities.

Very High Prevalence of Right-to-Left Shunt on Transcranial Doppler in an Italian Family with Cerebral Autosomal Dominant Angiopathy with Subcortical Infarcts and Leukoencephalopathy

Background and Purpose: Cerebral autosomal dominant angiopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant hereditary disease whose clinical expression is a stepwise subcortical vascular dementia. Initial presentation of the disease involves transient or stabilized focal neurological deficits, migraine and mood changes. Recently, a high prevalence of right-to-left shunt (RLS) due to patent foramen ovale has been reported in subjects with migraine. The aim of our study was to determine the prevalence of RLS in CADASIL with and without migraine. Methods: We performed transcranial Doppler with gaseous contrast in 5 members of an Italian family with CADASIL, diagnosed by means of genetic and skin biopsy criteria. We then compared the prevalence of RLS in 40 consecutive subjects with juvenile stroke, 80 asymptomatic subjects affected by migraine with aura and 50 normal controls. Results: A very high prevalence of RLS was found in CADASIL patients (4/5, 80%), as opposed to young subjects with ischemic stroke (15/40, 37%), asymptomatic subjects with migraine (32/80, 40%) and normal controls (8/50, 16%). All the subjects with CADASIL and migraine (4/4) showed RLS. The difference between CADASIL patients and controls was highly significant (p = 0.006). Conclusions: We suggest an association between CADASIL and RLS, possibly due to the abnormal development of the endocardial cushion influenced by Notch 3 mutation. Our hypothesis needs to be tested in larger samples.