Redox Status in Retinitis Pigmentosa

Retinitis pigmentosa (RP) is the most common form of inherited retinal dystrophy characterized by the progressive loss of vision. It is a rare disease. Despite being a genetic disease, its progression is influenced by oxidative damage and chemokines and cytokines released by the activated immune cells (e.g., macrophages or microglia). The role of oxidative stress is very important in the retina. Rods are the main consumers of oxygen (O2), so they are constantly exposed to oxidative stress and lipid peroxidation. According to the oxidative hypothesis, after rod death in the early stages of the disease, O2 would accumulate in large quantities in the retina, producing hyperoxia and favoring the accumulation of reactive oxygen species and reactive nitrogen species that would cause oxidative damage to lipids, proteins, and DNA, exacerbating the process of retinal degeneration. Evidence shows alterations in the antioxidant-oxidant state in patients and in animal models of RP. In recent years, therapeutic approaches aimed at reducing oxidative stress have emerged as useful therapies to slow down the progression of RP. We focus this review on oxidative stress and its relationship with the progression of RP.

Synergistic activation of AMPK prevents from polyglutamine-induced toxicity in Caenorhabditis elegans

Expression of abnormally long polyglutamine (polyQ) tracks is the source of a range of dominant neurodegenerative diseases, such as Huntington disease. Currently, there is no treatment for this devastating disease, although some chemicals, e.g., metformin, have been proposed as therapeutic solutions. In this work, we show that metformin, together with salicylate, can synergistically reduce the number of aggregates produced after polyQ expression in Caenorhabditis elegans. Moreover, we demonstrate that incubation polyQ-stressed worms with low doses of both chemicals restores neuronal functionality. Both substances are pleitotropic and may activate a range of different targets. However, we demonstrate in this report that the beneficial effect induced by the combination of these drugs depends entirely on the catalytic action of AMPK, since loss of function mutants of aak-2/AMPKα2 do not respond to the treatment. To further investigate the mechanism of the synergetic activity of metformin/salicylate, we used CRISPR to generate mutant alleles of the scaffolding subunit of AMPK, aakb-1/AMPKβ1. In addition, we used an RNAi strategy to silence the expression of the second AMPKβ subunit in worms, namely aakb-2/AMPKβ2. In this work, we demonstrated that both regulatory subunits of AMPK are modulators of protein homeostasis. Interestingly, only aakb-2/AMPKβ2 is required for the synergistic action of metformin/salicylate to reduce polyQ aggregation. Finally, we showed that autophagy acts downstream of metformin/salicylate-related AMPK activation to promote healthy protein homeostasis in worms.

Mutational spectrum of Duchenne muscular dystrophy in Spain: Study of 284 cases

INTRODUCTION

Duchenne muscular dystrophy (DMD) is a severe X-linked recessive neuromuscular disease that affects one in 3500 live-born males. The total absence of dystrophin observed in DMD patients is generally caused by mutations that disrupt the reading frame of the DMD gene, and about 80% of cases harbour deletions or duplications of one or more exons.

METHODS

We reviewed 284 cases of males with a genetic diagnosis of DMD between 2007 and 2014. These patients were selected from 8 Spanish reference hospitals representing most areas of Spain. Multiplex PCR, MLPA, and sequencing were performed to identify mutations.

RESULTS

Most of these DMD patients present large deletions (46.1%) or large duplications (19.7%) in the dystrophin gene. The remaining 34.2% correspond to point mutations, and half of these correspond to nonsense mutations. In this study we identified 23 new mutations in DMD: 7 large deletions and 16 point mutations.

CONCLUSIONS

The algorithm for genetic diagnosis applied by the participating centres is the most appropriate for genotyping patients with DMD. The genetic specificity of different therapies currently being developed emphasises the importance of identifying the mutation appearing in each patient; 38.7% of the cases in this series are eligible to participate in current clinical trials.

Genetics of the Charcot-Marie-Tooth disease in the Spanish Gypsy population: the hereditary motor and sensory neuropathy-Russe in depth

Four private mutations responsible for three forms demyelinating of Charcot-Marie-Tooth (CMT) or hereditary motor and sensory neuropathy (HMSN) have been associated with the Gypsy population: the NDRG1 p.R148X in CMT type 4D (CMT4D/HMSN-Lom); p.C737_P738delinsX and p.R1109X mutations in the SH3TC2 gene (CMT4C); and a G>C change in a novel alternative untranslated exon in the HK1 gene causative of CMT4G (CMT4G/HMSN-Russe). Here we address the findings of a genetic study of 29 Gypsy Spanish families with autosomal recessive demyelinating CMT. The most frequent form is CMT4C (57.14%), followed by HMSN-Russe (25%) and HMSN-Lom (17.86%). The relevant frequency of HMSN-Russe has allowed us to investigate in depth the genetics and the associated clinical symptoms of this CMT form. HMSN-Russe probands share the same haplotype confirming that the HK1 g.9712G>C is a founder mutation, which arrived in Spain around the end of the 18th century. The clinical picture of HMSN-Russe is a progressive CMT disorder leading to severe weakness of the lower limbs and prominent distal sensory loss. Motor nerve conduction velocity was in the demyelinating or intermediate range.

Guidelines for genetic study of aniridia

INTRODUCTION

Aniridia is a panocular disorder which occurs in 1/50,000 to 1/100,000 live births and can appear either in isolated form or in the context of a syndrome. Isolated aniridia is inherited as an autosomal dominant condition and is caused by mutations of the PAX6 gene. A variety of techniques and methodologies within molecular genetics and cytogenetics are used to study these mutations.

OBJECTIVE

To identify the different aspects of this disease and to provide a guide for proper genetic diagnosis leading to improved clinical management of the disease.

DEVELOPMENT

Aniridia is an autosomal dominant disease that primarily affects the iris, though it can impact most of the ocular structures. The disease is mainly caused by mutations in the PAX6 gene located on chromosome 11p13 which encodes a transcription factor that is involved in the development of the eye. Genetic analysis of aniridia is complex and requires the use of both molecular genetics and cytogenetics techniques. These procedures are indicated in all cases of aniridia. It is important bear certain clinical and technical aspects in mind prior to starting analysis or providing genetic counseling for patients and their families.

CONCLUSIONS

The use of molecular genetic techniques in the genetic diagnosis of aniridia enables patients and their families to receive better clinical management.

Acute perfusion changes after spontaneous SAH: a perfusion CT study

BACKGROUND

Perfusion computed tomography (CT) is a rapid technique that allows the measurement of acute disturbances in local and global cerebral blood flow in patients suffering stroke and spontaneous subarachnoid haemorrhage (SAH). The purpose of this study was to establish the relationship between different measures of brain perfusion made on dynamic-contrast CT reconstructions performed as soon as SAH has been diagnosed and the severity of the bleeding determined by the clinical grade, the extent of the bleeding and the outcome of the patients.

METHODS

After the diagnosis of SAH by conventional CT, a perfusion CT was performed before CT angiography. All imaging studies were performed on a six-slice spiral CT scanner. All images were analysed using perfusion software developed by Philips, which produces perfusion CT quantitative data based on temporal changes in signal intensity during the first pass of a bolus of an iodinated contrast agent. Measurements of mean transient time (MTT), time to peak (TTP), cerebral blood volume (CBV) and cerebral blood flow (CBF) in volumes of interest corresponding to territories perfused by the major cerebral arteries were performed. Different data regarding severity of the bleeding-such as level of consciousness, amount of bleeding in conventional CT-were collected. All poor-grade patients received a ventriculostomy catheter so that ICP recordings were obtained. Also, the occurrence of delayed cerebral ischaemia (DCI) was recorded. Outcome was assessed by the Glasgow Outcome Scale 6 months after the bleeding. For statistical analysis, non-parametric correlations between variables were performed.

FINDINGS

Thirty-nine patients have been included in the study since January 2007. In SAH patients there are increasing perfusion abnormalities as the severity of the bleeding increases. The most affected perfusion parameters are TTP and MTT, as they significantly increase with the clinical severity of the bleeding and the total volume of bleeding (P < 0.01, Spearman's Rho). When average MTT time is increased over 5.9 s there is a 20-fold (95% CI = 2.1-182) risk of poor outcome. All patients presenting this MTT time suffered from DCI. This value has a positive predictive value of 100% for DCI and 90% for a poor outcome.

CONCLUSIONS

SAH causes cerebral blood flow abnormalities even in the acute phase of the illness, consisting mainly of an increase in circulation times (TTP and MTT), which are correlated with the severity of the bleeding.

Intravitreal ranibizumab for symptomatic drusenoid pigment epithelial detachment without choroidal neovascularization in age-related macular degeneration

Background:

The aim of our study was to evaluate the functional and anatomic outcomes of intravitreal ranibizumab for the treatment of symptomatic drusenoid pigment epithelial detachment without choroidal neovascularization in age-related macular degeneration.

Methods:

This was a prospective, single-center, uncontrolled, interventional pilot study. Six consecutive eyes (six patients) with drusenoid pigment epithelial detachment with a visual acuity of 20/63 to 20/100 and no evidence of choroidal neovascularization in age-related macular degeneration participated. Patients were given at least one intravitreal ranibizumab injection and were followed for a mean of 66.67 ± 10.3 weeks. Main outcome measures included best-corrected visual acuity (BCVA) measured by Early Treatment Diabetic Retinopathy Study charts and optical coherence tomography, and central macular thickness measured by optical coherence tomography.

Results:

The mean number of intravitreal ranibizumab injections was 3.0 at the end of follow-up. Regarding BCVA and optical coherence tomography, 33.3% of eyes gained between 19 and 21 letters of BCVA, with a median decrease in central macular thickness of 21 μm. There was a statistically significant difference between baseline and final BCVA (P = 0.046). There was a positive correlation between intraretinal fluid by optical coherence tomography and improved BCVA after intravitreal ranibizumab. Metamorphopsia disappeared completely after the first injection in all subjects, with no further recurrences. No patient developed choroidal neovascularization or atrophic changes.

Conclusion:

Intravitreal ranibizumab demonstrated anatomic and functional benefit in patients with symptomatic drusenoid pigment epithelial detachment without choroidal neovascularization in age-related macular degeneration. Further long-term, randomized, controlled trials should be performed to confirm our preliminary results.

MYH7 gene tail mutation causing myopathic profiles beyond Laing distal myopathy

OBJECTIVE

To describe a wide range of clinical and pathologic myopathic profiles associated with the p.K1729del mutation in the MYH7 gene, known to cause Laing distal myopathy.

METHODS

A study conducted in the Safor region (Spain), setting of a large cluster of patients. Clinical, neurophysiologic, muscle imaging, and muscle biopsy studies and MYH7 gene sequencing were investigated in 32 patients from 4 kindreds. Data from 36 deceased or nonexamined patients were collected from hospital records or relatives.

RESULTS

Onset ranged from congenital to the 6th decade. All patients presented weakness of great toe/ankle dorsiflexors and many had associated neck flexor, finger extensor, and mild facial weakness. In most cases, involvement of proximal and axial muscles was observed either clinically or by muscle imaging, sometimes giving rise to scapuloperoneal and limb-girdle syndromes. Disabling myalgias, skeletal deformities, and dilated cardiomyopathy in one patient were associated features. Life expectancy was not reduced but the spectrum of disability ranged from asymptomatic to wheelchair confined. Electromyographic neurogenic features were frequently recorded. Muscle fiber type disproportion, core/minicore lesions, and mitochondrial abnormalities were the most relevant pathologic alterations. All patients carried the p.K1729del mutation in MYH7.

CONCLUSIONS

The p.K1729del mutation in the MYH7 gene expresses notable clinical variability and electromyographic and pathologic features that can lead to the misdiagnosis of neurogenic atrophies, congenital myopathies, or mitochondrial myopathies. Mutations in genes encoding other sarcomeric and reticulo-sarcoplasmic proteins involved in calcium regulation share pathologic characteristics with our patients, suggesting a possible pathogenetic connection.

The c.859G>C variant in the SMN2 gene is associated with types II and III SMA and originates from a common ancestor

Homozygous mutations of the telomeric SMN1 gene lead to degeneration of motor neurons causing spinal muscular atrophy (SMA). A highly similar centromeric gene (SMN2) can only partially compensate for SMN1 deficiency. The c.859G>C variant in SMN2 has been recently reported as a positive disease modifier. We identified the variant in 10 unrelated chronic SMA patients with a wide spectrum of phenotypes ranging from type II patients who can only sit to adult walkers. Haplotype analysis strongly suggests that the variant originated from a common ancestor. Our results confirm that the c.859G>C variant is a milder SMN2 allele and predict a direct correlation between SMN activity and phenotypic severity.

Insights into the role of microRNAs in cardiac diseases: from biological signalling to therapeutic targets

microRNAs have recently opened new pathways to explain gene expression and disease biology in many scenarios, including cardiac diseases. microRNAs are endogenous small non-coding RNAs that mediate post-transcriptional repression or messenger RNA degradation. By annealing to inexactly complementary sequences in the 3' untranslated region of the target messenger RNA, protein level is down-regulated. Several microRNAs appear to act cooperatively through multiple target sites in one gene and, conversely, most microRNAs can target several genes. miR-133 and miR-1 are specifically expressed in cardiac and skeletal muscle and control myogenesis, cardiac development, cardiac performance and cardiomyocyte hypertrophy (mainly by tuning transcription factors and other growth-related targets). They also modulate the expression of certain cardiac ion channels and related proteins with proarrhythmic effect. Besides them, other microRNAs have been shown to exert influence on the myocardial growth, the electrical balance and the angiogenesis processes that take place in the heart. Bioinformatics is a useful tool to identify potential targets of a given microRNA, although there is still substantial concern about their reliability. Experimental manipulation of microRNAs has provided a tantalizing basis to speculate that future research on microRNAs may yield important progress in the prevention of sudden cardiac death and in the treatment of cardiac heart failure. However, the final effect of the blockage of microRNAs in vivo remains unclear, since each of them can target hundreds of genes with different intensity. The era of the microRNAs in cardiovascular diseases has just started.

[Genetic counselling in visual and auditory disorders]

PURPOSE

Inherited retinal dystrophies and hearing loss disorders have a broad clinical and genetic heterogeneity. Over the last decade there have been major advances in our understanding of the molecular pathology of these diseases; currently over 200 genes and loci are known to be involved in retinal disorders, and over 60 genes/loci are causative for hearing impairment.

METHODS

Genetic testing is crucial for confirming the diagnosis at a molecular level. It also allows a more precise prognosis to be made of the future clinical evolution, as well as an accurate genetic and reproductive counselling, and raises the possibility of creating genetically homogeneous groups of patients for future clinical trials.

RESULTS

The high number of genes responsible for these disorders makes molecular testing overwhelming in terms of cost, time and technical effectiveness, and no centre offers testing of all known genes. Several diagnostic tools have emerged recently to circumvent this problem.

CONCLUSIONS

In this report, we review the vast genetic heterogeneity of retinal dystrophies and hypoacusis, recent advances in gene discovery, the different DNA-based microarray technologies available for molecular testing, their benefits and limitations, and novel therapeutic approaches.

The p.R1109X mutation in SH3TC2 gene is predominant in Spanish Gypsies with Charcot-Marie-Tooth disease type 4

Charcot-Marie-Tooth (CMT) disease type 4 (CMT4) is the name given to autosomal recessive forms of hereditary motor and sensory neuropathy (HMSN). When we began this study, three genes or loci associated with inherited peripheral neuropathies had already been identified in the European Gypsy population: HMSN-Lom (MIM 601455), HMSN-Russe (MIM 605285) and the congenital cataracts facial dysmorphism neuropathy syndrome (MIM 604168). We have carried out genetic analyses in a series of 20 Spanish Gypsy families diagnosed with a demyelinating CMT disease compatible with an autosomal recessive trait. We found the p.R148X mutation in the N-myc downstream-regulated gene 1 gene to be responsible for the HMSN-Lom in four families and also possible linkage to the HMSN-Russe locus in three others. We have also studied the CMT4C locus because of the clinical similarities and showed that in 10 families, the disease is caused by mutations located on the SH3 domain and tetratricopeptide repeats 2 (SH3TC2) gene: p.R1109X in 20 out of 21 chromosomes and p.C737_P738delinsX in only one chromosome. Moreover, the SH3TC2 p.R1109X mutation is associated with a conserved haplotype and, therefore, may be a private founder mutation for the Gypsy population. Estimation of the allelic age revealed that the SH3TC2 p.R1109X mutation may have arisen about 225 years ago, probably as the consequence of a bottleneck.

Identification of 14 novel mutations in the long isoform of USH2A in Spanish patients with Usher syndrome type II

Mutations in USH2A gene have been shown to be responsible for Usher syndrome type II, an autosomal recessive disorder characterised by hearing loss and retinitis pigmentosa. USH2A was firstly described as consisting of 21 exons, but 52 novel exons at the 3' end of the gene were recently identified. In this report, a mutation analysis of the new 52 exons of USH2A gene was carried out in 32 unrelated patients in which both disease-causing mutations could not be found after the screening of the first 21 exons of the USH2A gene. On analysing the new 52 exons, fourteen novel mutations were identified in 14 out of the 32 cases studied, including 7 missense, 5 frameshift, 1 duplication and a putative splice-site mutation.

Aneurysm re-rupture during computed tomography angiography

Re-rupture of cerebral aneurysms during conventional angiography, demonstrated by contrast leakage into the extravascular space, is well known and well documented. However, the occurrence of this complication during computed tomography (CT) angiographic examinations has rarely been published despite its extensive use. We present the clinical and radiological features of a rebleeding event during a CT angiographic study. No hemodynamic or contrast-related factors can be evoked predisposing to he occurrence of this complication during this imaging technique. This, along with the short study time, may explain the rarity of this coincidence.

Mutation profile of the MYO7A gene in Spanish patients with Usher syndrome type I

Usher syndrome type I is the most severe form of Usher syndrome. It is an autosomal recessive disorder characterized by profound congenital sensorineural deafness, retinitis pigmentosa, and vestibular abnormalities. Mutations in the myosin VIIA gene (MYO7A) are responsible for Usher syndrome type 1B (USH1B). This gene is thought to bear greatest responsibility for USH1 and, depending on the study, has been reported to account for between 24% and 59% of USH1 cases. In this report a mutation screening of the MYO7A gene was carried out in a series of 48 unrelated USH1 families using single strand conformation polymorphism analysis (SSCP) and direct sequencing of those fragments showed an abnormal electrophoretic pattern. Twenty-five mutations were identified in 23 out of the 48 families studied (47.9%). Twelve of these mutations were novel, including five missense mutations, three premature stop codons, three frameshift, and one putative splice-site mutation. Based on our results we can conclude there is an absence of hot spot mutations in the MYO7A gene and that this gene plays a major role in Usher syndrome.

Mutation screening of USH3 gene (clarin-1) in Spanish patients with Usher syndrome: low prevalence and phenotypic variability

Usher syndrome type III is an autosomal recessive disorder clinically characterized by the association of retinitis pigmentosa (RP), variable presence of vestibular dysfunction and progressive hearing loss, being the progression of the hearing impairment the critical parameter classically used to distinguish this form from Usher syndrome type I and Usher syndrome type II. Usher syndrome type III clinical subtype is the rarest form of Usher syndrome in Spain, accounting only for 6% of all Usher syndrome Spanish cases. The gene responsible for Usher syndrome type III is named clarin-1 and it is thought to be involved in hair cell and photoreceptor cell synapses. Here, we report a screening for mutations in clarin-1 gene among our series of Usher syndrome Spanish patients. Clarin-1 has been found to be responsible for the disease in only two families: the first one is a previously reported family homozygous for Y63X mutation and the second one, described here, is homozygous for C40G. This accounts for 1.7% of Usher syndrome Spanish families. It is noticeable that, whereas C40G family is clinically compatible with Usher syndrome type III due to the progression of the hearing loss, Y63X family could be diagnosed as Usher syndrome type I because the hearing impairment is profound and stable. Thus, we consider that the progression of hearing loss is not the definitive key parameter to distinguish Usher syndrome type III from Usher syndrome type I and Usher syndrome type II.

Phase II trial of cisplatin and capecitabine in patients with squamous cell carcinoma of the head and neck, and correlative study of angiogenic factors

The combination of cisplatin and capecitabine was evaluated in patients with recurrent or unresectable squamous cell carcinoma of the head and neck (HNSCC), and outcome parameters were correlated with the expression of thymidine phosphorylase (TP), thymidilate syntetase (TS), vascular endothelial growth factor receptor (VEGFR) 1–3, and microvessel density (MVD). Patients with recurrent or unresectable HNSCC were eligible if they had received prior neoadjuvant chemotherapy, concurrent chemo-radiotherapy, or no prior systemic therapy. Patients received cisplatin (75 mg m⁻² day 1), and capecitabine (2000 mg m⁻² day 1–14) every 3 weeks. A total of 41 patients received 194 cycles. In all, 16 complete responses (39%) and 12 partial responses (29%) were documented, for an overall response rate of 68% (95% CI, 53–80%). Grade 3–4 uncomplicated neutropenia was documented in five subjects. Asthenia, anorexia, hand–foot syndrome, and constipation were the most frequent nonhaematologic events. Median progression-free and overall survival were 6.4 and 12.6 months. Cytoplasmic TP expression was more prevalent in patients with a laryngeal location vs other, and in patients with a recurrence vs primary disease. Microvessel density count was higher in patients with recurrent vs primary disease. The combination of cisplatin and capecitabine is effective in recurrent or unresectable HNSCC, and shows a manageable toxicity.

Epidemiology of Usher syndrome in Valencia and Spain

OBJECTIVE

To obtain epidemiological data on the prevalence of the different types of Usher syndrome (US) in Spain, since these data were missing; to estimate the proportion of sporadic cases among simplex families, and calculate the prevalence of the Usher syndrome in a homogeneous population from Eastern Spain (3,875,234 inhabitants) that is representative of the Spanish population.

METHODS

Otological, ophthalmological and genetic studies were performed in 89 US patients from 46 families and subjected to statistical and segregation analysis.

RESULTS

41.6% of them suffered US type I, 46.1% type II, and in 12.3% the classification remains unclear. The estimated prevalence for the Province of Valencia was 4.2/100,000. There was a notable excess of male-only affected multiplex sibships in our sample that could be attributable to an X-linked inheritance.

CONCLUSIONS

The number of families with USI type was similar to that of families with USII type. The estimated prevalence for the Province of Valencia is in agreement with other reports in which the estimate for the prevalence of US ranges from 1.8 to 6.2/100,000.

Estudio genético molecular del síndrome de Usher en España

Usher syndrome (USH) associates deafness and retinitis pigmentosa (RP). It is a disease both clinically and genetically heterogeneous. It is inherited as an autosomal recessive trait and its prevalence makes it the most frequent association of hearing loss and RP. Clinically Usher syndrome is divided into type I (USH1), II (USH2) and III (USH3), according to the severity of hearing loss, age of onset of RP and the existence or not of vestibular dysfunction. There are at least 7 different localizations for USH1 and 5 genes have been identified. For USH2, 3 loci and 2 genes have been reported and USH3 is due to Clarin-1 gene. Our aim is to perform a clinical and genetic characterization of all Usher syndrome patients in Spain.

Giant cell reparative granuloma of the occipital bone

Giant cell reparative granuloma (GCRG) is a non-neoplastic fibrous lesion with unevenly distributed multinucleated giant cells, areas of osseous metaplasia and hemorrhage. The small bones of the hands and feet are the most common sites, followed by the vertebral bodies and craniofacial bones. In the craniofacial bones GCRG has been reported in the temporal bone, in the frontal bone and paranasal sinus. However, to the best of our knowledge no case has been reported in the occipital bone. We report on the imaging findings and pathological features of a GCRG of the occipital bone and discuss the differential diagnosis of this entity in this particular location, especially with giant cell tumor because of the therapeutic and prognostic implications.

Molecular genetic analysis of HLA-DR and -DQ alleles in Spanish patients with melanoma

Controversial data have been reported about HLA alleles and susceptibility to melanoma. The relationship between distribution of HLA alleles in patients with melanoma and susceptibility to tumour was analysed, to study the possible correlation between HLA class II DQA1, DQB1 and DRBI genes and melanoma in a Spanish population. Genomic DNA from 82 patients with melanoma and 367 random healthy donors, from the same geographic area, were typed by PCR-SSP (sequence specific primers). The patients were also divided into different groups according to the age and presence of cancer relatives, and compared with the controls. None of these HLA class II alleles showed significant positive or negative associations with either the overall population of patients with melanoma or the considered subgroups. Moreover, values for relative risk of DQB1*0301, DQB1*0302, DQB1*0303, DQB*05, DQA1*0401, DQA1*0101/0104 and DRB*08, which have been reported to be increased or decreased in patients with melanoma, were very low and of no statistical significance. Our results indicate that HLA class II alleles may not contribute to a strong susceptibility to melanoma in the Spanish population, although further studies on larger series are needed to corroborate this. Key words:

Induction chemotherapy with paclitaxel, cisplatin and 5-fluorouracil for squamous cell carcinoma of the head and neck: long-term results of a phase II trial

BACKGROUND

The aim of this study was to evaluate the efficacy and toxicity of a combination of paclitaxel, cisplatin and 5-fluorouracil (PPF) as induction chemotherapy in patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN).

METHODS

Seventy patients with previously untreated stage III-IV SCCHN were included in this phase II trial. Induction treatment consisted of a maximum of three outpatient courses of paclitaxel 175 mg/m(2) as a 3-h infusion on day 1, cisplatin 100 mg/m(2) on day 2, and 5-fluorouracil (5-FU) 500-750 mg/m(2)/day as a 24-h continuous infusion on days 2-6, repeated every 3 weeks. The 5-FU dose was reduced from 750 mg/m(2)/day to 500 mg/m(2)/day due to the excessive toxicity observed in the first 14 patients enrolled. Local treatment consisted of radiotherapy and/or surgery.

RESULTS

Two-hundred-and-one cycles were administered to 70 patients. The main toxicities of PPF were neutropenia (grade 4, 14%; febrile neutropenia, 4%), peripheral neuropathy (grade 2-3, 14%) and catheter-associated venous thrombosis (7%). There were three early deaths (two from neutropenic sepsis and one from pulmonary embolism), and 13 patients required hospitalization due to toxicity. Other side effects included mucositis, anorexia, diarrhea, myalgias and alopecia. The overall response rate to PPF was 88%, including 59% complete responses (CR) and 29% partial responses. The CR rates at the primary tumor and neck lymph nodes were 74% and 62%, respectively. With a median follow-up of 51 months (range 40-63 months), the estimated 5-year time-to-disease progression and overall survival rates were 56% and 44%, respectively.

CONCLUSIONS

The PPF regimen has major antitumor activity and is associated with manageable toxicity as induction treatment in SCCHN patients. The high complete response rate and favorable long-term outcome justify further evaluation of this chemotherapy combination.

Parosteal osteosarcoma of the skull

Parosteal osteosarcoma of the skull is a distinct surface bone tumor, with a better prognosis than conventional osteosarcoma. The most common location is on the surface of the distal femur which accounts for 46-66% of the cases. The presentation in the skull is uncommon and there are few cases reported in the literature. We describe the case of a man who developed a parosteal osteosarcoma arising from the occipital bone with extension to the parietal bone. The patient was operated and had a complete tumor resection.

Trisomy rescue by postzygotic unbalanced (X;14) translocation in a girl with dysmorphic features

In this report we present the clinical features and molecular and cytogenetic findings in a female with partial trisomy 14q. Molecular and cytogenetic studies allowed us to determine that the extra 14q material (of paternal origin) was translocated postzygotically onto the maternal X chromosome. Consequently, only the derivative X chromosome was inactivated, although inactivation apparently did not spread over the entire chromosome 14q. This partial inactivation makes the present case unusual, giving rise to phenotypic features absent in other patients with partial trisomy 14q, typically restricted to the distal part of the chromosome.

Identification of novel RP2 mutations in a subset of X-linked retinitis pigmentosa families and prediction of new domains

X-linked Retinitis Pigmentosa (XLRP) shows a huge genetic heterogeneity with almost five distinct loci on the X chromosome. So far, only two XLRP genes have been identified, RPGR (or RP3) and RP2, being mutated in approximately 70% and 10% of the XLRP patients. Clinically there is no clearly significative difference between RP3 and RP2 phenotypes. In the attempt to assess the degree of involvement of the RP2 gene, we performed a complete mutation analysis in a cohort of patients and we identified five novel mutations in five different XLRP families. These mutations include three missense mutations, a splice site mutation, and a single base insertion, which, because of frameshift, anticipates a stop codon. Four mutations fall in RP2 exon 2 and one in exon 3. Evidence that such mutations are different from the 21 RP2 mutations described thus far suggests that a high mutation rate occurs at the RP2 locus, and that most mutations arise independently, without a founder effect. Our mutation analysis confirms the percentage of RP2 mutations detected so far in populations of different ethnic origin. In addition to novel mutations, we report here that a deeper sequence analysis of the RP2 product predicts, in addition to cofactor C homology domain, further putative functional domains, and that some novel mutations identify RP2 amino acid residues which are evolutionary conserved, hence possibly crucial to the RP2 function.

Localization of non-specific X-linked mental retardation gene (MRX73) to Xp22.2

Clinical and molecular studies are reported on a family (MRX73) of five males with non-specific X-linked mental retardation (XLMR). A total of 33 microsatellite and RFLP markers was typed. The gene for this XLMR condition was been linked to DXS1195, with a lod score of 2.36 at theta = 0. The haplotype and multipoint linkage analyses suggest localization of the MRX73 locus to an interval of 2 cM defined by markers DXS8019 and DXS365, in Xp22.2. This interval contains the gene of Coffin-Lowry syndrome (RSK2), where a missense mutation has been associated with a form of non-specific mental retardation. Therefore, a search for RSK2 mutations was performed in the MRX73 family, but no causal mutation was found. We hypothesize that another unidentified XLMR gene is located near RSK2.

[Type 8 spinocerebellar ataxia. A report of a family]

INTRODUCTION

Over the past decade, from the genetic point of view, several of the entities included in the group of hereditary ataxias have been identified. We report a Spanish family with type 8 spinocerebellar ataxia (SCA8), one of the most recent hereditary ataxias to be described from the clinical and genetic points of view.

CLINICAL CASE

A 59 year old woman consulted us complaining of progressive dysarthria and unsteady gait. The only abnormal findings on neurological examination were those of cerebellar involvement. The patient s mother had a similar condition, characterized by difficulty in speaking which started when she was 62 years old and progressed to anarthria. Cranial magnetic resonance showed the presence of cerebellar atrophy with no signs of atrophy of the brainstem. On electromyographic studies there were no signs of neuropathy. Visual, auditory and sensory evoked potentials were normal. Genetic studies showed expansion of trinucleotide CTG (112 repetitions in the expanded allele and 28 repetitions in the normal allele) on the gene responsible for SCA8.

CONCLUSION

SCA8 should be included in the differential diagnosis of progressive cerebellar syndromes, especially when changes in speech predominate with regard to other cerebellar signs.

DNA interstrand cross-linking efficiency and cytotoxic activity of novel cadmium(II)-thiocarbodiazone complexes

We have prepared mono- and binuclear complexes of Zn(II) and Cd(II) with bis(2-pyridyl aldehyde) thiocarbodiazone (H(2)L(1)) and bis(methyl 3-pyridyl ketone) thiocarbodiazone (H(2)L(2)). Cytotoxicity data against the ovarian tumor cell line A2780cisR (acquired resistance to cisplatin) indicate that the mononuclear complex Cd/H(2)L(2) (1) and the binuclear complex Cd(2)/H(2)L(1) (4) are able to circumvent cisplatin resistance and that their cytotoxic activity does not substantially vary after depletion of intracellular levels of glutathione. Moreover, DNA binding studies show that complexes 1 and 4 have higher efficiency than cisplatin at forming DNA interstrand cross-links in both naked pBR322 plasmid and A2780cisR cellular DNA. Interestingly, the thiocarbodiazone ligands alone do not show the biological properties of complexes 1 and 4. Altogether these results suggest that DNA interstrand cross-link formation by compounds 1 and 4 might be related with their cytotoxic activity in cisplatin-resistant cells. We think that compounds 1 and 4 may represent a novel structural lead for the development of cadmium cytotoxic agents capable of improving antitumor activity in cisplatin-resistant tumors.

Fatal cerebral venous sinus thrombosis as major complication of metastatic cervical mass: computed tomography and magnetic resonance findings

Cerebral venous sinus thrombosis is an uncommon but potentially lethal condition, with mortality between 5.5-30 per cent. It was previously associated with infections of the orbit, mastoid or face, but, after the advent of antibiotics, the most common causes include neoplasms, dehydration, oral contraceptives, coagulopathies, collagen diseases, and pregnancy and the puerperium. We report a case of fatal cerebral venous sinus thrombosis in a 68-year-old patient with a metastatic cervical mass, who developed internal jugular vein thrombosis that progressed cranially to transverse and sagittal sinus thrombosis.

Prevalence of 2314delG mutation in Spanish patients with Usher syndrome type II (USH2)

The Usher syndrome (USH) is a group of autosomal recessive diseases characterized by congenital sensorineural hearing loss and retinitis pigmentosa. Three clinically distinct forms of Usher syndrome have so far been recognized and can be distinguished from one another by assessing auditory and vestibular function. Usher syndrome type II (USH2) patients have congenital moderate-to-severe nonprogressive hearing loss, retinitis pigmentosa, and normal vestibular function. Genetic linkage studies have revealed genetic heterogeneity among the three types of USH, with the majority of USH2 families showing linkage to the USH2A locus in 1q41. The USH2A gene (MIM 276901) has been identified: three mutations, 2314delG, 2913delG, and 4353-54delC, were initially reported in USH2A patients, the most frequent of which is the 2314delG mutation. It has been reported that this mutation can give rise to typical and atypical USH2 phenotypes. USH2 cases represent 62% of all USH cases in the Spanish population, and 95% of these cases have provided evidence of linkage to the USH2A locus. In the present study, the three reported mutations were analyzed in 59 Spanish families with a diagnosis of USH type II. The 2314delG was the only mutation identified in our population: it was detected in 25% of families and 16% of USH2 chromosomes analyzed. This study attempts to estimate the prevalence of this common mutation in a homogeneous Spanish population.

Identification of two rare variants (G-->A at nucleotide 721; C-->T at nucleotide 5200) in the rhodopsin gene. Mutations in brief no. 187. Online

The authors report two new rare DNA sequence variants in the Rhodopsin gene. This gene is involved in the pathogenesis of some retinal hereditary disorders as Retinitis Pigmentosa. These rare variants are G-->A at nucleotide 721 of the non-coding region and C-->T at nucleotide 5200 within codon 323 which does not alter the aminoacid cysteine. Therefore, they are not implicated in the development of the Retinitis Pigmentosa disease.

Identification of three novel mutations in the MYO7A gene

Three new mutations in the myosin VIIA gene involved in the pathogenesis of Usher syndrome type Ib are reported. These mutations are K1080X in exon 25, E1170K in exon 28, and Y1719C in exon 37. It is presumed that these mutations are involved in the Usher syndrome Ib phenotype.

Arachnoiditis ossificans. Diagnosis with helical computed tomography

Arachnoiditis ossificans (AO) is a rare entity in which ossification of the leptomeninges occurs. This report illustrates a patient with AO of the cervical and dorsal spine, diagnosed by helical computed tomography with multiplanar reconstruction. It demonstrates the value of computed tomography in diagnosing calcified plaques and the utility of multiplanar reconstruction in giving an exact anatomic reference to neurosurgeon.

Detection of a novel Cys628STOP mutation of the myosin VIIA gene in Usher syndrome type Ib

A Spanish family with three Usher I syndrome-affected members was linked to markers located on chromosome 11q. A search for mutations on the myosin VIIA gene revealed a novel mutation (Cys628STOP) on exon 16 segregating with the disorder in a homozygous state. This nonsense mutation could be responsible for the disease since it leads to a truncated protein that presumably has no function.

Phase II trial of cisplatin and gemcitabine in advanced squamous-cell carcinoma of the head and neck

BACKGROUND

To evaluate the toxicity profile and efficacy of cisplatin combined with gemcitabine in patients with irresectable locally recurrent or metastatic squamous cell carcinoma of the head and neck.

PATIENTS AND METHODS

Gemcitabine was given at a dose of 800 mg/m2 on days 1, 8 and 15, plus cisplatin at a dose of 50 mg/m2 on days 1 and 8; every four weeks.

RESULTS

Twenty-four patients with a median age of 59 years (range 42-74) were included. All patients were evaluable for toxicity and 22 patients were assessable for response. Eleven cases had advanced recurrent locoregional disease while 13 patients had metastatic disease. One CR (4.7%) and four PR (18%) were observed, for an overall response rate of 22.7% (95% CI: 8%-42%). The main toxicity was hematological: neutropenia grade 3-4 in 28% of the cycles and thrombocytopenia grade 3-4 in 16%. The most significant non-hematological toxicity was asthenia grade 2-3 in 24% of the cycles.

CONCLUSIONS

This cisplatin plus gemcitabine combination schedule has a favourable toxicity profile with a discrete activity in patients with locally recurrent or metastatic squamous-cell carcinoma of the head and neck.

Ala397Asp mutation of myosin VIIA gene segregating in a Spanish family with type-Ib Usher syndrome

In the current study, 12 Spanish families affected by type-I Usher syndrome, that was previously linked to chromosome 11q, were screened for the presence of mutations in the N-terminal coding portion of the motor domain of the myosin VIIA gene by single-strand conformation polymorphism analysis of the first 14 exons. A mutation (Ala397Asp) segregating with the disease was identified, and several polymorphisms were also detected. It is presumed that the other USHIB mutations in these families could be located in the unscreened regions of the gene.

Linkage analysis in Usher syndrome type I (USH1) families from Spain

Usher syndrome (USH) is an autosomal recessive hereditary disorder characterised by congenital sensorineural hearing loss and gradual visual impairment secondary to retinitis pigmentosa (RP). The disorder is clinically and genetically heterogeneous. With regard to Usher type I (USH1), several subtypes have been described, the most frequent being USH1B located on chromosome 11q13.5. Of 18 USH1 families studied by linkage analysis, 12 (67%) showed significant lod score values for locus D11S527 (Zmax=14.032, theta=0.000) situated on chromosome 11q. Our findings suggest considerable genetic heterogeneity in the Spanish USH1 population. It is important to note that one of our families linked to the USH1B locus shows interesting intrafamilial clinical variability. As regards the remaining six USH1 families, the linkage analysis did not provide conclusive data, although two of them show slight linkage to markers located on chromosome 3q (Zmax=1.880, theta=0.000 for D3S1279), the same location that had previously been assigned to some USH3 families.

Pediatric brain tumors: loss of heterozygosity at 17p and TP53 gene mutations

Cytogenetic and molecular analyses of primitive neuroectodermal tumors (PNETs) of the central nervous system (CNS) have demonstrated material losses of 17p, the region that contains the TP53 gene, as the most frequent abnormality. Mutations in the TP53 gene are, however, very rare in these tumors. These findings strongly suggest that another, as yet unidentified, gene on 17p may be involved. We performed a search for loss of heterozygosity (LOH) on 17p by microsatellite markers on 26 childhood CNS tumors as well as TP53 gene mutations (exons 5-8) by single-strand conformational polymorphism analysis on 41 pediatric brain tumor samples of distinct histologic types. LOH was detected in 10 cases: 7 PNET, 2 astrocytomas, and 1 glioblastoma multiforme. In 4 of the PNETs the losses were limited to more distal markers. On the other hand, TP53 mutations were detected in 6 of 41 samples studied. Our results not only confirm the low penetrance of the TP53 gene on pediatric CNS tumors, but also provide further evidence of a putative tumor suppressor gene distal to TP53, between markers (D17S938, D17S926) and 17pter, specifically taking part in the development of PNET.

Genetic localisation of mental retardation with spastic diplegia to the pericentromeric region of the X chromosome: X inactivation in female carriers

We report on two brothers and one maternal cousin with severe mental retardation, microcephaly, short stature, cryptorchidism, and spastic diplegia. The patients were born to normal and non-consanguineous parents. All other members of the family, almost exclusively females, were clinically normal, suggesting X linked inheritance. By multipoint linkage analysis with markers spanning the whole X chromosome, we have tentatively assigned the underlying genetic defect to Xp11.4-q21, achieving a maximum lod score of 1.3. This localisation overlaps MRXS3, a syndromic form of mental retardation resembling that found in the family described here, although with a milder presentation. We discuss the possibility that both phenotypes might be allelic variants of the same gene localised in the pericentromeric region of the X chromosome. Analysis of the X inactivation pattern in one potential and three obligate carrier females showed non-random inactivation of the allele linked to the disease. This finding may be interpreted as: (1) a negative selection effect on cells bearing the mutation on the active X chromosome; (2) both the disease causing gene and the X inactivation centre are simultaneously affected by the same alteration, a deletion for instance; or (3) the skewed inactivation is the consequence of an independent event randomly associated with the disease. In any case, the observation of consistent X inactivation supports X linkage of the disease.

Mutational analysis of the MPZ, PMP22 and Cx32 genes in patients of Spanish ancestry with Charcot-Marie-Tooth disease and hereditary neuropathy with liability to pressure palsies

Charcot-Marie-Tooth disease (CMT) and hereditary neuropathy with liability to pressure palsies (HNPP) are two inherited peripheral neuropathies. The most prevalent mutations are a reciprocal 1.5-Mb duplication and 1.5-Mb deletion, respectively, at the CMT1A/HNPP locus on chromosome 17p11.2. Point mutations in the coding region of the myelin genes, peripheral myelin protein 22 (PMP22), myelin protein zero (MPZ) or connexin 32 (Cx32) have been reported in CMT patients, including CMT type 1 (CMT1), CMT type 2 (CMT2) and Déjérine-Sottas neuropathy (DS) patients, and only in the coding region of PMP22 in HNPP families lacking a deletion. We have investigated point and small mutations in the MPZ, PMP22 and Cx32 genes in a series of patients of Spanish ancestry: 47 CMT patients without duplications, and 5 HNPP patients without deletions. We found 15 different mutations in 16 CMT patients (34%). Nine different mutations in ten patients were detected in the Cx32 gene, this being the most frequently involved gene in this series, whereas five mutations involved the MPZ gene and only one the PMP22 gene. Six out of nine nucleotide substitutions in the Cx32 gene involved two codons encoding arginine at positions 164 and 183, suggesting that these two codons may constitute two Cx32 regions prone to mutate in the Spanish population. Analysis of HNPP patients revealed a 5' splicing mutation in intron 1 of the PMP22 gene in a family with autosomal dominance, which confirms allelic heterogeneity in HNPP. Ectopic mRNA analysis on leukocytes suggests that this mutation might behave as a null allele.

An autosomal dominant retinitis pigmentosa family with close linkage to D7S480 on 7q

Retinitis pigmentosa is the most prevalent inherited disorder of the retina. It can be autosomal dominant (adRP), autosomal recessive (arRP) or X-linked (XLRP). A form of adRP mapping to chromosome 7q was reported in a large Spanish pedigree. We have typed DNA from the members of another Spanish family for polymorphic markers from the known candidate genes. Positive lod scores were obtained only for the markers located on 7q31-35, giving a maximum lod score of 2.98 (3.01 by multipoint analysis) at theta = 0.00 for D7S480. A brief clinical evaluation is given.