Autosomal recessive spinocerebellar ataxia SCAR8/ARCA1: first families detected in Spain.

INTRODUCTION: Autosomal recessive spinocerebellar ataxia type 8 (ARCA1/SCAR8) is caused by mutations of the SYNE1 gene. The disease was initially described in families from Quebec (Canada) with a phenotype of pure cerebellar syndrome, but in recent years has been reported with a more variable clinical phenotype in other countries. Cases have recently been described of muscular dystrophy, arthrogryposis, and cardiomyopathy due to SYNE1 mutations. OBJECTIVE: To describe clinical and molecular findings from 4 patients (3 men and one woman) diagnosed with ARCA1/SCAR8 from 3 Spanish families from different regions. MATERIAL AND METHODS: We describe the clinical, paraclinical, and genetic results from 4 patients diagnosed with ARCA1/SCAR8 at different Spanish neurology departments. RESULTS: Onset occurred in the third or fourth decade of life in all patients. After 15 years of progression, 3 patients presented pure cerebellar syndrome, similar to the Canadian patients; the fourth patient, with over 30 years' progression, presented vertical gaze palsy, pyramidal signs, and moderate cognitive impairment. In all patients, MRI studies showed cerebellar atrophy. The genetic study revealed distinct pathogenic SYNE1 mutations in each family. CONCLUSIONS: ARCA1/SCAR8 can be found worldwide and may be caused by many distinct mutations in the SYNE1 gene. The disease may manifest with a complex phenotype of varying severity.

Cerebellar Cognitive Affective Syndrome in Costa da Morte Ataxia (SCA36).

SCA36 is an autosomal dominant spinocerebellar ataxia (SCA) affecting many families from Costa da Morte, a northwestern region of Spain. It is caused by an intronic GGCCTG repeat expansion in NOP56. In order to characterize the cognitive and affective manifestations of this cerebellar disease, a group of 30 SCA36 mutation carriers (11 preataxic and 19 ataxic patients) were assessed with a comprehensive battery of standardized tests. Phonological verbal fluency - but not semantic fluency - was already mildly impaired in preataxic subjects. In ataxic patients, both phonological and semantic fluencies were significantly below normal. Depression, while more frequent and prominent in ataxic patients, was also often present in the preataxic stage. This is the first systematic study supporting the presence of a mild cerebellar cognitive and affective syndrome in SCA36. Routine evaluation of cognitive and emotional spheres in SCA36 patients as well as asymptomatic mutation carriers should allow early detection and timely therapeutic intervention.

Autosomal recessive spinocerebellar ataxia SCAR8/ARCA1: First families detected in Spain. / Heredoataxia cerebelosa recesiva ARCA1/SCAR8: primeras familias detectadas en España.

INTRODUCTION: Autosomal recessive spinocerebellar ataxia type 8 (ARCA1/SCAR8) is caused by mutations of the SYNE1 gene. The disease was initially described in families from Quebec (Canada) with a phenotype of pure cerebellar syndrome, but in recent years has been reported with a more variable clinical phenotype in other countries. Cases have recently been described of muscular dystrophy, arthrogryposis, and cardiomyopathy due to SYNE1 mutations. OBJECTIVE: To describe clinical and molecular findings from 4 patients (3 men and one woman) diagnosed with ARCA1/SCAR8 from 3 Spanish families from different regions. MATERIAL AND METHODS: We describe the clinical, paraclinical, and genetic results from 4 patients diagnosed with ARCA1/SCAR8 at different Spanish neurology departments. RESULTS: Onset occurred in the third or fourth decade of live in all patients. After 15 years of progression, 3 patients presented pure cerebellar syndrome, similar to the Canadian patients; the fourth patient, with over 30 years' progression, presented vertical gaze palsy, pyramidal signs, and moderate cognitive impairment. In all patients, MRI studies showed cerebellar atrophy. The genetic study revealed distinct pathogenic SYNE1 mutations in each family. CONCLUSIONS: ARCA1/SCAR8 can be found worldwide and may be caused by many distinct mutations in the SYNE1 gene. The disease may manifest with a complex phenotype of varying severity.

PLA2G6 mutations associated with a continuous clinical spectrum from neuroaxonal dystrophy to hereditary spastic paraplegia.

PLA2G6-associated neurodegeneration (PLAN) and hereditary spastic paraplegia (HSP) are 2 groups of heterogeneous neurodegenerative diseases. In this study, we report PLA2G6 gene mutations in 3 families from Turkey, Morocco, and Romania. Two affected Turkish siblings presenting HSP adds the disease to PLAN phenotypes. They were homozygous for the PLA2G6 missense c.2239C>T, p.Arg747Trp variant and the ages of onset were 9 and 21. Parkinsonism, dystonia or cognitive decline were not the clinical elements in these patients contrary to the cases that has been previously reported with the same variant, however, iron accumulation was evident in their cranial magnetic resonance imaging. The Moroccan patient was homozygous for a novel missense c.1786C>T, p.Leu596Phe variant and the Romanian patient had 2 novel mutations; c.1898C>T, p.Ala633Val and c.1765_1768del, p.Ser589ThrfsTer76. Both of these patients conformed better to childhood onset PLAN with the age of onset at 4 and 7 years, respectively. Interestingly, all identified mutations were affecting the highly conserved patatin-like phospholipase domain of the PLA2G6 protein.

Evaluating the Calling Performance of a Rare Disease NGS Panel for Single Nucleotide and Copy Number Variants.

INTRODUCTION: Variant detection protocols for clinical next-generation sequencing (NGS) need application-specific optimization. Our aim was to analyze the performance of single nucleotide variant (SNV) and copy number (CNV) detection programs on an NGS panel for a rare disease. METHODS: Thirty genes were sequenced in 83 patients with hereditary spastic paraplegia. The variant calls obtained with LifeScope, GATK UnifiedGenotyper and GATK HaplotypeCaller were compared with Sanger sequencing. The calling efficiency was evaluated for 187 (56 unique) SNVs and indels. Five multiexon deletions detected by multiple ligation probe assay were assessed from the NGS panel data with ExomeDepth, panelcn.MOPS and CNVPanelizer software. RESULTS: There were 48/51 (94%) SNVs and 1/5 (20%) indels consistently detected by all the calling algorithms. Two SNVs were not detected by any of the callers because of a rare reference allele, and one SNV in a low coverage region was only detected by two algorithms. Regarding CNVs, ExomeDepth detected 5/5 multi-exon deletions, panelcn.MOPs 4/5 and only 3/5 deletions were accurately detected by CNVPanelizer. CONCLUSIONS: The calling efficiency of NGS algorithms for SNVs is influenced by variant type and coverage. NGS protocols need to account for the presence of rare variants in the reference sequence as well as for ambiguities in indel calling. CNV detection algorithms can be used to identify large deletions from NGS panel data for diagnostic applications; however, sensitivity depends on coverage, selection of the reference set and deletion size. We recommend the incorporation of several variant callers in the NGS pipeline to maximize variant detection efficiency.

Spinocerebellar ataxia 36 (SCA36): «Costa da Morte ataxia¼. / La ataxia espinocerebelosa 36 (SCA36): «Ataxia da Costa da Morte¼.

INTRODUCTION-OBJECTIVE: To describe the history of the discovery of SCA36 and review knowledge of this entity, which is currently the most prevalent hereditary ataxia in Galicia (Spain) owing to a founder effect. DEVELOPMENT: SCA36 is an autosomal dominant hereditary ataxia with late onset and slow progression. It presents with cerebellar ataxia, sensorineural hearing loss, and discrete motor neuron impairment (tongue atrophy with denervation, discrete pyramidal signs). SCA36 was first described in Japan (Asida River ataxia) and in Galicia(Costa da Morte ataxia). The condition is caused by a genetic mutation (intronic hexanucleotide repeat expansion) in the NOP56 gene on the short arm of chromosome 20 (20p13). Magnetic resonance image study initially shows cerebellar vermian atrophy that subsequently extends to the rest of the cerebellum and finally to the pontomedullary region of the brainstem without producing white matter lesions. Peripheral nerve conduction velocities are normal, and sensorimotor evoked potential studies show delayed conduction of stimuli to lower limbs. In patients with hearing loss, audiometric studies show a drop of >40dB in frequencies exceeding 2,500Hz. Auditory evoked potential studies may also show lack of waves I and II. CONCLUSIONS: Costa da Morte ataxia or SCA36 is the most prevalent SCA in the Spanish region of Galicia. Given the region's history of high rates of emigration, new cases may be diagnosed in numerous countries, especially in Latin America. Genetic studies are now available to patients and asymptomatic carriers. Since many people are at risk for this disease, we will continue our investigations aimed at elucidating the underlying pathogenic molecular mechanisms and discovering effective treatment.

Exome sequencing is a useful diagnostic tool for complicated forms of hereditary spastic paraplegia.

Hereditary spastic paraplegias constitute a heterogeneous group of neurodegenerative diseases encompassing pure and complicated forms, for which at least 52 loci and 31 causative genes have been identified. Although mutations in the SPAST gene explain approximately 40% of the pure autosomal dominant forms, molecular diagnosis can be challenging for the sporadic and recessive forms, which are often complicated and clinically overlap with a broad number of movement disorders. The validity of exome sequencing as a routine diagnostic approach in the movement disorder clinic needs to be assessed. The main goal of this study was to explore the usefulness of an exome analysis for the diagnosis of a complicated form of spastic paraplegia. Whole-exome sequencing was performed in two Spanish siblings with a neurodegenerative syndrome including upper and lower motor neuron, ocular and cerebellar signs. Exome sequencing revealed that both patients carry a novel homozygous nonsense mutation in exon 15 of the SPG11 gene (c.2678G>A; p.W893X), which was not found in 584 Spanish control chromosomes. After many years of follow-up and multiple time-consuming genetic testing, we were able to diagnose these patients by making use of whole-exome sequencing, showing that this is a cost-efficient diagnostic tool for the movement disorder specialist.

Medical genomics: The intricate path from genetic variant identification to clinical interpretation.

The field of medical genomics involves translating high throughput genetic methods to the clinic, in order to improve diagnostic efficiency and treatment decision making. Technical questions related to sample enrichment, sequencing methodologies and variant identification and calling algorithms, still need careful investigation in order to validate the analytical step of next generation sequencing techniques for clinical applications. However, the main foreseeable challenge will be interpreting the clinical significance of the variants observed in a given patient, as well as their significance for family members and for other patients. Every step in the variant interpretation process has limitations and difficulties, and its quote of contribution to false positive and false negative results. There is no single piece of evidence enough on its own to make firm conclusions on the pathogenicity and disease causality of a given variant. A plethora of automated analysis software tools is being developed that will enhance efficiency and accuracy. However a risk of misinterpretation could derive from biased biorepository content, facilitated by annotation of variant functional consequences using previous datasets stored in the same or linked repositories. In order to improve variant interpretation and avoid an exponential accumulation of confounding noise in the medical literature, the use of terms in a standard way should be sought and requested when reporting genetic variants and their consequences. Generally, stepwise and linear interpretation processes are likely to overrate some pieces of evidence while underscoring others. Algorithms are needed that allow a multidimensional, parallel analysis of diverse lines of evidence to be carried out by expert teams for specific genes, cellular pathways or disorders.

SNOMED CT module-driven clinical archetype management.

OBJECTIVE: To explore semantic search to improve management and user navigation in clinical archetype repositories. METHODS: In order to support semantic searches across archetypes, an automated method based on SNOMED CT modularization is implemented to transform clinical archetypes into SNOMED CT extracts. Concurrently, query terms are converted into SNOMED CT concepts using the search engine Lucene. Retrieval is then carried out by matching query concepts with the corresponding SNOMED CT segments. RESULTS: A test collection of the 16 clinical archetypes, including over 250 terms, and a subset of 55 clinical terms from two medical dictionaries, MediLexicon and MedlinePlus, were used to test our method. The keyword-based service supported by the OpenEHR repository offered us a benchmark to evaluate the enhancement of performance. In total, our approach reached 97.4% precision and 69.1% recall, providing a substantial improvement of recall (more than 70%) compared to the benchmark. CONCLUSIONS: Exploiting medical domain knowledge from ontologies such as SNOMED CT may overcome some limitations of the keyword-based systems and thus improve the search experience of repository users. An automated approach based on ontology segmentation is an efficient and feasible way for supporting modeling, management and user navigation in clinical archetype repositories.

Cerebrotendinous xanthomatosis in Spain: clinical, prognostic, and genetic survey.

BACKGROUND AND PURPOSE: Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder caused by mutations in the CYP27A1 gene resulting in sterol-27-hydroxylase deficiency. Current information about CTX is based mainly on case reports, with only few large series reported. Although perceived as a potentially treatable condition, efficacy of chenodeoxycholic acid plus statin therapy remains unclear. To perform a nationwide survey of confirmed cases, with a thorough analysis of genotype-phenotype data and prognostic factors. METHODS: Retrospective review of the clinical and epidemiological aspects and mutations of all the patients diagnosed since 1992 in the main reference centers for genetic testing of CTX in Spain. RESULTS: Twenty-five patients from 19 families were identified. An average delay of 19 years was observed between symptom onset and clinical diagnosis. Two main clinical subgroups were recognizable: a classic form (cerebellar and other supratentorial symptoms) and a spinal form (chronic myelopathy). Cholestanol levels did not correlate with clinical presentation, severity or response to therapy. Despite treatment, five patients died during follow-up, one to 4 years after diagnosis. Thirteen different mutations were identified, with a higher frequency of p.R395C in Northwestern Spain and p.R405W in Southern Spain. None of the mutations could be associated with a particular clinical feature combination or prognosis. CONCLUSIONS: This is the first nationwide extensive series of CTX reported in Spain. The higher number of cases in some areas suggests a possible founder effect. Spinal forms had a less severe prognosis. A delayed diagnosis could contribute to the lack of significant response to treatment.

Neurofibromatosis without Neurofibromas: Confirmation of a Genotype-Phenotype Correlation and Implications for Genetic Testing.

Neurofibromatosis type 1 (NF1) is a multisystem disease with autosomal dominant inheritance and complete penetrance diagnosed by clinical findings. Cutaneous neurofibromas are present in almost all adult patients in the dermis, epidermis or along the peripheral nerves. Plexiform neurofibromas are subcutaneous or deep lesions involving nerve plexuses or roots. Neurofibromas can degenerate into malignant tumors, with important prognostic implications. NF1 shows a broad clinic variability even within a single family. Exceptions are cases reporting the in-frame microdeletion c.2970_2972delAAT, presenting with the typical pigmentary features of NF1, but no cutaneous or plexiform neurofibromas. We report a patient with a de novo c.2970_2972delAAT mutation who had few café-au-lait spots, only 2 of which measured >15 mm, axillary and submammary freckling, a flat angioma extending over the neck, arm and trunk, a high arched palate, micrognathia, macrocephaly, pes cavus and scoliosis. There was complete absence of observable cutaneous neurofibromas as well as external plexiform neurofibromas. She had had epileptic seizures since childhood; however, a diagnosis of NF1 had not been confirmed until she was 38, partly due to the paucity of characteristic cutaneous stigmata. We confirm the association of the c.2970_2972delAAT mutation in NF1 with a particular clinical phenotype, especially with lack of detectable neurofibromas. For an appropriate management of patients and family counseling, molecular study of the NF1 gene should be considered in patients not fulfilling NIH criteria when other features suggestive of NF1 are present. In the absence of neurofibromas, starting NF1 testing with the screening of exon 17 may be worthwhile.

Asesoramiento genético en Neurología: un problema complejo que necesita regulación / Genetic counselling in Neurology: A complex problem that requires regulation

Introducción: La expansión de los estudios genéticos está transformando la práctica de la Neurología y enfrenta a los servicios clínicos con nuevos retos, como la articulación del asesoramiento genético. La amplitud de los conocimientos tanto clínicos como moleculares precisos, así como la necesidad de una evaluación psicológica y apoyo familiar, especialmente en los análisis predictivos y planificación reproductiva, hacen necesario un enfoque multidisciplinar. Desarrollo: Las características principales de las enfermedades neurodegenerativas de base genética son el elevado nivel de especialización requerido —por tratarse de enfermedades poco comunes y de difícil diagnóstico— junto con su carácter generalmente progresivo, la ausencia de tratamientos eficaces, la problemática generada por la posibilidad de estudios predictivos y la interpretación de los resultados genéticos. El objetivo del asesoramiento genético es proporcionar la información suficiente y objetiva para que cada individuo pueda tomar sus propias decisiones sobre el estudio genético. Debe incluir la evaluación de aspectos psicológicos y de comunicación familiar. El programa PICOGEN del Hospital Clinic de Barcelona para el análisis y asesoramiento genético en demencias es un buen ejemplo de una estrategia integrada capaz de abordar esta nueva situación asistencial en Neurología. Lamentablemente, este programa es una excepción en España y los pacientes con enfermedades neurogenéticas y sus familias no tienen garantizada habitualmente una asistencia adecuada.Conclusiones: El asesoramiento genético es un acto clínico per se, que precisa de un espacio, tiempo y recursos suficientes. Implica una participación multidisciplinar, atención a los aspectos psicológicos y familiares y no se puede llevar a cabo correctamente en el seno de una consulta rutinaria estándar de Neurología (AU)

Introduction: The generalization of genetic studies is transforming the practice of Neurology and confronts the clinical departments with new challenges, such as the organization of genetic counseling. The requirement of specialized knowledge, both clinical and molecular, as well as the need for psychological evaluation and family support, especially for predictive testing and reproductive planning, makes a multidisciplinary approach mandatory.Development: The main characteristics of genetic neurodegenerative diseases are the high level of required specialization — since these disorders are often rare and of difficult diagnosis— together with a generally progressive course, unavailability of effective treatment, the issues generated by predictive testing and the interpretation of genetic testing. The aim of geneticcounseling is to provide sufficient and objective information for each individual to make their own decision on genetic testing. It must touch upon psychological aspects and family communication.The PICOGEN program from the Clinic Hospital in Barcelona for genetic testing and counseling of dementias is a good example of integrated strategy capable of managing this new clinical scenario in neurology. Unfortunately, this program is an exception in Spain and the patients with neurogenetic disorders and their families usually do not have guaranteed access to an appropriate care. Conclusions: Genetic counseling is a unique clinical activity that requires provision of enough time, space and resources to be developed. It implies multidisciplinary participation, due attention to psychological and family issues, and cannot be carried out adequately in a routine Neurology clinic. Legislation is needed to promote a correct articulation of genetic counselingin our country with guarantee of quality and equity (AU)

Prevalence of parkinsonism and Parkinson's disease in the Arosa Island (Spain): a community-based door-to-door survey.

There are scarce epidemiological data on parkinsonism in Spain. Since the Arosa Island community (Northwestern Spain) has been for centuries relatively isolated, it represents a potentially useful setting to undercover genetic factors with a founder effect, as well as local environmental influences. We performed a one-stage door-to-door survey in the Arosa Island in 2004 to determine the prevalence of parkinsonism and Parkinson's disease (PD) in the population aged 65 years or over. Out of 41 individuals detected with parkinsonism, 15 were diagnosed with PD (36.6%), 13 with drug induced parkinsonism (31.7%), seven with vascular parkinsonism (17.1%), four patients had parkinsonism with associated features (9.8%) and two had unspecified parkinsonism (4.9%). We obtained a crude prevalence rate of parkinsonism of 5.44% (adjusted rate: 4.73%) and a crude prevalence rate of PD of 1.99% (adjusted rate 1.7%); both prevalence rates increased with advancing age. The prevalence rate for parkinsonism was higher than that in similar populations of Spain and other European countries while that for PD was in the range obtained from these populations. Among PD cases, 26.7% (n=4) were undiagnosed before the survey. Most cases of drug-induced parkinsonism were secondary to neuroleptics and had not been previously diagnosed. The relatively high proportion of undiagnosed drug-induced parkinsonisms and PD is surprising in a public health system which is free and universal. The lack of excess of late-onset PD among Arosans does not support the existence of specific genetic or environmental factors contributing to PD in this particular geographical area.

[Usefulness of cholestanol levels in the diagnosis and follow-up of patients with cerebrotendinous xanthomatosis]. / Utilidad de los niveles de colestanol en el diagnóstico y seguimiento de los pacientes con xantomatosis cerebrotendinosa.

INTRODUCTION: cerebrotendinous xanthomatosis (CTX) is an autosomal recessive disease caused by a deficiency of mitochondrial enzyme sterol 27-hydrolylase. Such a deficiency results in a reduced production of chenodeoxycholic acid and in an increased formation of cholestanol. It is clinically characterized by cataracts, diarrhoea, xanthomas, premature arteriosclerosis and a number of progressive neurological symptoms. Although cholestanol levels are used for the diagnosis of CTX, their correlation with the clinical symptoms and their prognostic usefulness have not been assessed so far. METHODS: we reviewed 14 CTX patients diagnosed between 1995 and 2008 in two reference centres for the genetic diagnosis of this disorder, whose cholestanol levels had been recorded. We studied the main demographic, clinical and therapeutical data and their correlation with plasma cholestanol levels. RESULTS: the average cholestanol level at diagnosis was 105.8 µmol/l. These levels did not correlate with any neurological symptoms or with disability at diagnosis scored by the EDSS. After treatment, all patients achieved a significant reduction in plasma cholestanol levels (average reduction of 91 µmol/l in an average follow-up of 34 months), although only one patient remained clinically stable. CONCLUSIONS: high cholestanol levels are very useful for diagnosis of CTX but they do not have a prognostic value (they do not correlate with severity). Normalisation of cholestanol levels is not always associated with clinical stabilisation. However, follow-up of cholestanol levels can be useful for the dose adjustment.

Genetic counselling in neurology: a complex problem that requires regulation.

INTRODUCTION: The generalization of genetic studies is transforming the practice of Neurology and confronts the clinical departments with new challenges, such as the organization of genetic counseling. The requirement of specialized knowledge, both clinical and molecular, as well as the need for psychological evaluation and family support, especially for predictive testing and reproductive planning, makes a multidisciplinary approach mandatory. DEVELOPMENT: The main characteristics of genetic neurodegenerative diseases are the high level of required specialization - since these disorders are often rare and of difficult diagnosis - together with a generally progressive course, unavailability of effective treatment, the issues generated by predictive testing and the interpretation of genetic testing. The aim of genetic counseling is to provide sufficient and objective information for each individual to make their own decision on genetic testing. It must touch upon psychological aspects and family communication. The PICOGEN program from the Clinic Hospital in Barcelona for genetic testing and counseling of dementias is a good example of integrated strategy capable of managing this new clinical scenario in neurology. Unfortunately, this program is an exception in Spain and the patients with neurogenetic disorders and their families usually do not have guaranteed access to an appropriate care. CONCLUSIONS: Genetic counseling is a unique clinical activity that requires provision of enough time, space and resources to be developed. It implies multidisciplinary participation, due attention to psychological and family issues, and cannot be carried out adequately in a routine Neurology clinic. Legislation is needed to promote a correct articulation of genetic counseling in our country with guarantee of quality and equity. This includes training of the necessary health professionals, clarification of competences and provision of resources to the institutions for the development of such programs.

[Disorders affecting the emotional sphere and impulse control in Parkinson's disease]. / Alteraciones de la esfera emocional y el control de los impulsos en la enfermedad de Parkinson.

INTRODUCTION: Parkinson's disease (PD) is associated with mood and behavioral symptoms contributing to morbidity and reduced quality of life of the patients. Most characteristic are depression, anxiety and impulse control disorder. DEVELOPMENT: Identification and treatment of neuropsychiatric symptoms is necessary for an appropriate management of PD. Affective symptoms may be the initial manifestation of PD, are highly prevalent and pathogenically complex. Impulse control disorders are usually not a spontaneous complaint, so asking about these symptoms may be the only way to detect and treat a serious socio-familial problem. Pharmacological treatment of these manifestations is difficult to balance with an adequate control of motor symptoms. Psychological support from early stages and throughout the evolution of PD is fundamental. CONCLUSIONS: Neurologist and other healthcare professionals treating PD patients need to be aware of behavioral and emotional manifestations of the disease. This will lead to an appropriate patient management and better adaptation of the familial and social situation.

Association study of the serotoninergic system in migraine in the Spanish population.

In order to evaluate the contribution of 19 serotonin-related genes to the susceptibility to migraine in a Spanish population we performed a case-control association study of 122 single nucleotide polymorphisms (SNPs), selected according to genetic coverage parameters, in 528 migraine patients -308 with migraine without aura (MO) and 220 with migraine with aura (MA)- and 528 sex-matched migraine-free controls. The single-marker analysis identified nominal associations with the migraine phenotype or with the MO or MA subtypes. The multiple-marker analysis revealed risk haplotypes in three genes that remained significantly associated with migraine after correction by permutations. Two-marker risk haplotypes were identified in the HTR2B (rs16827801T-rs10194776G) and MAOA (rs3027400G-rs2072743C) genes conferring susceptibility to MO, and a four-marker haplotype in DDC was specific of MA (rs2329340A-rs11974297C-rs2044859T-rs11761683G). The present study supports the involvement of HTR2B and MAOA genes in the genetic predisposition to MO, while DDC might confer susceptibility to MA. These results suggest a differential involvement of serotonin-related genes in the genetic background of MO and MA.

[Behavioral disorders in Parkinson's disease. Genetic, pharmacological and medico-legal aspects]. / Trastornos del comportamiento en la enfermedad de Parkinson. Aspectos genéticos, farmacológicos y médico-legales.

INTRODUCTION: Patients with Parkinson's disease (PD) may present neuropsychiatric and conduct disorders at different stages of the development of the disease that make treatment even more difficult. DEVELOPMENT: The neurologist must be on the lookout for the possible appearance of alterations affecting impulse control, even from the early stages of the disease, so as to be able to prevent them or to plan a suitable adjustment of treatment. Some of the most common impulsivity disorders include hypersexuality, compulsive gambling and other addictive behaviours which, if left undetected and untreated, can end up having a destructive effect on the patient's socio-familial surroundings. Psychotic disorders (hallucinations, delusions) are often associated to advanced phases of PD and to the effect of dopamine therapy, and they are associated to a higher morbidity and mortality rate. Factors of a genetic or pharmacogenetic nature or a gene-environment interaction may account for the different individual susceptibility to disorders in the neuropsychiatric realm among patients with PD. It is wise to bear in mind the possible medico-legal implications that may stem from behavioral disorders, both for the patient and his or her family and for the physician, because situations could arise that trigger conflicts between confidentiality and preventing third parties from being harmed, as well as harm that can be attributed to the side effects of medicines. CONCLUSIONS: The specialist must be familiar with, foresee and propose suitable treatment for behavioral and neuropsychiatric disorders in PD with potential medico-legal implications.