Expanding the spectrum of SOX1-antibodies in neuropathy: the coexistence of anti-SOX1 and Guillain-Barré syndrome-a case report.

BACKGROUND AND AIMS: Antibodies against SOX1 (or anti-glial nuclear antibody, AGNA) are partially characterized onconeural antibodies, firstly described in association with small cell lung cancer (SCLC). Lambert-Eaton myasthenic syndrome is the most frequent paraneoplastic syndrome (PNS) found in patients with anti-SOX1-antibody positivity. Other associations are chronic axonal polyneuropathy, paraneoplastic limbic encephalitis, and paraneoplastic cerebellar degeneration. METHODS: We describe a case of Guillain-Barré syndrome (GBS) with classical demyelinating phenotype associated with a positivity for anti-SOX1-antibodies. RESULTS: A therapy with intravenous immunoglobulin led to progressive clinical improvement. After 12 months, clinical and neurophysiological pictures showed complete recovery. A thorough paraneoplastic screening was negative for underlying tumors. CONCLUSIONS: This is the first case of GBS associated with anti-SOX1-antibodies described in literature. Although the concept of paraneoplastic GBS is controversial, different cases have been reported and GBS is considered a non-classical paraneoplastic syndrome. Our case expands the anti-SOX1-antibody clinical spectrum with relevant implications for the clinical practice.

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.

New onset status epilepticus in influenza associated encephalopathy: The presenting manifestation of genetic generalized epilepsy.

We hereby present a case of a young woman with no history of seizures or epilepsy who experienced a de novo generalized Non Convulsive Status Epilepticus (NCSE) followed by encephalopathy lasting for several days during influenza B infection. Influenza can have a broad spectrum of presentation ranging from an uncomplicated illness to many serious conditions as is the case of influenza associated encephalitis/encephalopathy (IAE). In this context however, it is possible to observe seizures and/or status epilepticus as the presenting manifestation of a genetic generalized epilepsy.

Contribution of the N-acetyltransferase 2 polymorphism NAT2*6A to age-related hearing impairment.

BACKGROUND: Age-related hearing impairment (ARHI) is the most common sensory impairment in older people, affecting 50% of those aged 80 years. The proportion of older people is increasing in the general population, and as a consequence, the number of people affected with ARHI is growing. ARHI is a complex disorder, with both environmental and genetic factors contributing to the disease. The first studies to elucidate these genetic factors were recently performed, resulting in the identification of the first two susceptibility genes for ARHI, NAT2 and KCNQ4. METHODS: In the present study, the association between ARHI and polymorphisms in genes that contribute to the defence against reactive oxygen species, including GSTT1, GSTM1 and NAT2, was tested. Samples originated from seven different countries and were combined into two test population samples, the general European population and the Finnish population. Two distinct phenotypes for ARHI were studied, Z(low) and Z(high), representing hearing in the low and high frequencies, respectively. Statistical analysis was performed for single polymorphisms (GSTM1, GSTT1, NAT2*5A, NAT2*6A, and NAT2*7A), haplotypes, and gene-environment and gene-gene interactions. RESULTS: We found an association between ARHI and GSTT1 and GSTM1 in the Finnish population sample, and with NAT2*6A in the general European population sample. The latter finding replicates previously published data. CONCLUSION: As replication is considered the ultimate proof of true associations in the study of complex disorders, this study provides further support for the involvement of NAT2*6A in ARHI.

[Occupational accidents, work performance and obstructive sleep apnea syndrome (OSAS)]. / Infortuni e performances sul lavoro in lavoratori affetti da sindrome delle apnee ostruttive nel sonno (OSAS).

Although many patients with obstructive sleep apnea syndrome (OSAS) form part of the work force, the impact of OSAS on occupational accidents and on work performance is unclear. To address this issue, we investigated 100 referents workers without OSAS (50 blue-collar and 50 white-collar) and 331 workers affected by OSAS (144 blue-collar and 187 white-collar). Workers affected by OSAS had been involved in occupational accidents more often than referents (27.2% vs. 20%). The mean number of accidents/year was slightly higher in blue-collar workers with OSAS and significantly higher (p=0.013) in white-collar workers with OSAS than referents. Furthermore, workers with OSAS referred more impairments in work performance as difficulties in memory (p=0.000), vigilance (p=0.000), concentration (p=0.000), performing monotonous tasks (p=0.000), responsiveness (p=0.000), learning new tasks (0.006) and manual ability (p=0.023), with the mean number of impairments being higher (p=0.000) in workers with a more severe OSAS (referents = 0.32; mild OSAS = 1.11; severe OSAS = 1.70). These results suggest OSAS increases the risk of occupational accidents and impaired work performance. Given the impact of OSAS on fitness for duty assessment, occupational physicians should be aware of it and could play a strategic role in its diagnosis, in monitoring treatment, and in providing appropriate information.

Consensus for tinnitus patient assessment and treatment outcome measurement: Tinnitus Research Initiative meeting, Regensburg, July 2006.

There is widespread recognition that consistency between research centres in the ways that patients with tinnitus are assessed and outcomes following interventions are measured would facilitate more effective co-operation and more meaningful evaluations and comparisons of outcomes. At the first Tinnitus Research Initiative meeting held in Regensburg in July 2006 an attempt was made through workshops to gain a consensus both for patient assessments and for outcome measurements. It is hoped that this will contribute towards better cooperation between research centres in finding and evaluating treatments for tinnitus by allowing better comparability between studies.

Familial aggregation of tinnitus: a European multicentre study.

INTRODUCTION AND AIM: Tinnitus is a common condition affecting approximately 20% of the older population. There is increasing evidence that changes in the central auditory system following cochlear malfunctioning are responsible for tinnitus. To date, few investigators have studied the influence of genetic factors on tinnitus. The present report investigates the presence of a familial effect in tinnitus subjects. METHODS: In a European multicentre study, 198 families were recruited in seven European countries. Each family had at least 3 siblings. Subjects were screened for causes of hearing loss other than presbyacusis by clinical examination and a questionnaire. The presence of tinnitus was evaluated with the question "Nowadays, do you ever get noises in your head or ear (tinnitus) which usually last longer than five minutes". Familial aggregation was tested using three methods: a mixed model approach, calculating familial correlations, and estimating the risk of a subject having tinnitus if the disorder is present in another family member. RESULTS: All methods demonstrated a significant familial effect for tinnitus. The effect persisted after correction for the effect of other risk factors such as hearing loss, gender and age. The size of the familial effect is smaller than that for age-related hearing impairment, with a familial correlation of 0.15. CONCLUSION: The presence of a familial effect for tinnitus opens the door to specific studies that can determine whether this effect is due to a shared familial environment or the involvement of genetic factors. Subsequent association studies may result in the identification of the factors responsible. In addition, more emphasis should be placed on the effect of role models in the treatment of tinnitus.

Mapping of a new autosomal dominant non-syndromic hearing loss locus (DFNA43) to chromosome 2p12.

Hearing impairment (HI) is the most frequent sensory defect with wide genetic heterogeneity. Approximately 80% of genetic hearing loss is non-syndromic and 15-25% of exhibit autosomal dominant inheritance. We analysed an Italian three generation family in which non-syndromic hearing impairment is transmitted as an autosomal dominant trait. Onset of HI in all affected subjects occurred in the second decade of life, with subsequent gradual progression from moderate to profound loss. HI was bilateral and symmetrical, involving all frequencies. After exclusion of the known DFNA loci with markers from the Hereditary Hearing Loss Homepage (URL: http://dnalab-www.uia.ac.be/dnalab/hhh), a genome wide scan was carried out using 358 highly informative microsatellite markers. Significant linkage (Zmax=4.21, theta=0) was obtained with chromosome 2p12 markers. The results were confirmed by multipoint analysis (Zmax=4.51), using the location score method. Haplotype analysis defined a 9.6 cM disease gene interval on chromosome 2 without overlap with the other identified loci. Fine mapping and identification of candidate genes are in progress.

Mapping of a new autosomal dominant nonsyndromic hearing loss locus (DFNA30) to chromosome 15q25-26.

Hearing impairment is the most common inherited human sensory defect. Nonsyndromic Hearing Impairment (NSHI) is the most genetically heterogeneous trait known. Over 70 loci have been mapped and a total of 19 genes have been identified. We report here a novel locus (DFNA 30) for autosomal dominant NSHI that we mapped to chromosome 15q25-26 in an Italian four-generation family. The haplotype analysis has identified a critical interval of 18 cM between markers D15S151 and D15S130. This region does not overlap with DFNB16 locus but partially coincides with the otosclerosis (OTS) locus. Localisation of the locus DFNA30 is a first step towards the identification of the gene.

Exploring the clinical and epidemiological complexity of GJB2-linked deafness.

GJB2 mutation analysis was performed in 179 unrelated subjects with sporadic or familial hearing loss (HL). Among 57 families, 18 showed a vertical transmission of HL, the disease being present in two or three generations. Besides 155 nonsyndromic cases, 24 patients presenting with extra-auditory clinical signs were included in the molecular study. GJB2 mutation analysis was also performed in 19 subjects with an anamnestic history of perinatal risks factors for acquired HL. The 35delG mutation accounted for 22.1% of analyzed chromosomes in sporadic cases and 39.4% in familial cases; 35delG prevalence reached 41% in autosomal recessive and 44.4% in pseudodominant pedigrees. Two novel GJB2 mutations were identified in compound heterozygosity with 35delG allele (D159V, 284ins/dup[CACGT]). Two 35delG homozygous subjects were identified among HL cases classified as environmental in origin. Four patients 35delG heterozygous (35delG/V95M, 35delG/L90P, 35delG/167delT, and 35delG/?) and two homozygous presented with extra-auditory clinical signs involving different organs (skin, vascular system, hemopoietic lineages, and thyroid). In a high proportion of 35delG heterozygous HL patients (52%), no second GJB2 mutation was detected. The reported data highlight the complexity of the genetic epidemiology of GJB2-linked deafness, further enlarging the spectrum of situations in which GJB2 mutation analysis should be performed. The presence of extra-auditory signs in a significant portion of GJB2-mutated patients suggests the possibility that GJB2 loss of function could contribute to clinical phenotypes presenting in association with deafness. This hypothesis deserves further investigation. The failure to identify a presumed partnering GJB2 mutation in a high proportion of deaf patients remains a challenging problem to be clarified.

An introduction to the genetics of normal and defective hearing.

The recent rapid development of molecular biology techniques applied to the genetics of normal and defective hearing shed a new light on old questions regarding hearing and deafness. Genes are DNA sequences that determine characteristics, normally by specifying the sequence of aminoacids in a protein. The majority of genes is located in the chromosomes (human chromosomes have perhaps 80,000 pairs of genes). In addition there are 37 mithochondrial genes which are inherited only from the mother. One method used to identify candidate genes based on their function or pattern of tissue expression involves the construction of cDNA libraries from the target organ or tissue, in this case from the cochlea. The construction and characterization of cochlear cDNA libraries from humans and other species provide an important resource for rapid identification of cochlear genes involved in normal hearing and hearing disorders. Studies of the molecular genetics of the inner ear are hampered by the relative inaccessibility of the cochlea, by the limited number of cochlear and vestibular cells, and by our inability to maintain many of these cell types in long-term cultures. Several rodent inner-ear cDNA libraries and a human foetal cochlear cDNA library have already been constructed. Human and rodent cochlea-subtracted cDNA libraries are very useful for identifying genes controlling the development and maintenance of hearing. cDNA libraries constructed at different stages of development, and subtracted from each other, could be instrumental in identifying genes important at each stage of cochlear development. In addition, these libraries have the potential of fostering the identification of other proteins unique to the cochlea and will contribute to the identification, characterization, and functional analysis of these cochlea-specific proteins. Another important application of cDNA libraries is in identifying hearing-loss genes. Once the candidate gene for a given type of hearing loss is cloned and decoded, the structure of its protein product can be determined. This will provide insights into the biochemical function of the gene product in normal cochlear tissue, and will show why the genetic mutation results in hearing loss, that is, the recent identification of the myosin VIIa gene in Usher type IB. In addition, through the use of homologous recombination and transgenic technology, in vivo mouse models of inner-ear genetic disorders can be created. To date, 350 different genetic conditions associated with hearing impairment have been described, and during the past five years several of the genes involved in these form have already been mapped and identified.

Efficacy and tolerability of brodimoprim in bacterial otitis media in children. Controlled study versus cefaclor.

78 pediatric patients affected by acute otitis media were selected and randomized into two balanced groups of treatment: brodimoprim, at the dosage of 200 mg once-a-day on the first day and of 100 mg once-a-day on the following days, and cefaclor at a dosage of 40 mg/Kg/day in three doses. Brodimoprim resulted more efficacious in the reduction of symptoms, especially hypoacusis and tinnitus (p < 0.05 between treatments); tympanometry showed a higher number of normalizations in the brodimoprim group, without significant differences between treatments. Both drugs resulted active against most of isolated bacterial strains. Side effects were reported in 4 patients treated with brodimoprim and in 6 patients in the control group.

Achievements of the European Working Group on Genetics of Hearing Impairment.

Three years ago an European Working Group for the study of genetics of hearing impairment was founded with the aim to standardise terminology and protocols in order to collect families with genetic hearing impairments for a European-based epidemiological, clinical and genetic analysis. Hereditary hearing impairments include a large variety of genetic causes. The occurrence of the different forms is rare, but the overall genetic aetiology is thought to account for up to 50% of newborns' hearing impairment as well as several late onset, progressive cases. In the later years, several locations associated with non-syndromal hearing impairments and different mutations for the syndromic diseases have been identified. Five subgroups have been formed: Definitions and protocols, Epidemiology, Vestibular involvement, Otological and cranial malformations, Molecular biology. Meetings were organised for discussion and establishment of common ground work. Application of the agreed documents was performed to verify protocols. Final agreements were circulated by Infoletter (1-5). Informatic working tools on the Internet have been designed. Standardised definitions, audiological and vestibular protocols have been defined. Pilot studies using experimental protocols to identify informative carriers or to help clinical differentiation between non-syndromic forms have also been performed. Two web sites related to the work have been created. A description of phenotypes of locations identified has been defined. Joining forces to standardise definitions and protocols and collaboration between clinicians and geneticists has contributed considerably to progress in this field.

Identifying congenital hearing impairment: preliminary results from a comparative study using objective and subjective audiometric protocols.

To compare objective and subjective protocols assessing hearing loss in young children and evaluate frequency-specific hearing impairment through a comparison between auditory steady state responses (ASSR), auditory brainstem responses (ABR), transient otoacoustic emissions and conditioned orientation reflex responses (COR). Thirty-five hearing-impaired children (20 male and 15 female), aged between 14 months and 4 years, participated in the study. Hearing threshold levels and peripheral auditory function were assessed by measurements of ABR, ASSR, otoacoustic emissions and COR. The analysis of the COR and ASSR variables showed significant correlations in the majority of tested frequencies. The data highlight a characteristic of the COR procedure, which is an underestimation of the hearing threshold in comparison to the ASSR estimate. The data show that the COR threshold assessment follows the pattern of the other two established electrophysiological methods (ABR, ASSR). The correlation analyses did not permit evaluation of the precision of these estimates. Considering that the ASSR variables show a better relationship with ABR (higher correlation values) than COR, it might be advantageous to utilize the ASSR to gain frequency-specific information.