Efficient application of next-generation sequencing for the diagnosis of rare genetic syndromes.

Aims: The causes of intellectual disability, which affects 1%-3% of the general population, are highly heterogeneous and the genetic defect remains unknown in around 40% of patients. The application of next-generation sequencing is changing the nature of biomedical diagnosis. This technology has quickly become the method of choice for searching for pathogenic mutations in rare uncharacterised genetic diseases.

Mutation analysis of Wilson disease in the Spanish population -- identification of a prevalent substitution and eight novel mutations in the ATP7B gene.

Wilson disease (WD) is a copper metabolism disorder characterized by hepatic and/or neurological damage. More than 200 mutations in the ATP7B gene causing this autosomal recessive defect have been reported. In certain populations, a high prevalence of particular mutations allows rapid screening and diagnosis of the disease.

[Transient cerebral oedema associated to hypoglycaemia].

Introduction: In the adult, hypoglycaemia is documented as a consequence of overdose of insulin or oral hypoglycaemic agents. Neonatal hypoglycaemia is common but rarely symptomatic due to protective mechanisms. Very few reports on hypoglycaemic injury are available in adults and most of them in patients with poor outcome.

Pulmonary mass and multiple lung nodules mimicking a lung neoplasm as amiodarone-induced pulmonary toxicity.

Amiodarone is an effective anti-arrhythmic agent. However, during long-term therapy, patients can develop severe adverse pulmonary reactions that are potentially life-threatening. A case of amiodarone-induced pulmonary toxicity is presented in a 78-year-old woman.

Chromosomal abnormalities and polymorphisms in infertile men.

The aim of this study was to determine the prevalence of alterations and normal variable chromosome features in males from infertile couples. Karyotyping was performed to 84 men attending the infertility clinic at the Hospital Clinic i Provincial of Barcelona (Spain). Sex chromosome abnormalities were detected in 19 patients (26.

Paternal isodisomy 13 in a normal newborn infant after trisomy rescue evidenced by prenatal diagnosis.

Maternal and paternal uniparental disomy of chromosome 13 have been associated with normal phenotypes. We report on a new case of paternal isodisomy 13 in a phenotypically normal girl. Prenatal diagnosis had shown a 46,XX,-13,der(13;13) karyotype in chorionic villi and a 45,XX,der(13;13) karyotype in amniocytes and fetal blood.

Analysis of the polymorphic (GT)(n) repeat at the dopamine beta-hydroxylase gene in Spanish patients affected by schizophrenia.

The presence of a polymorphic (GT)(n) repeat, a microsatellite repeat, at the human dopamine beta-hydroxylase (DBH) gene had been previously investigated in healthy people and in schizophrenic patients. The different DBH genotypes had been found to be associated to different DBH biochemical function, but no differences were found in the allelic and genotype frequencies between schizophrenic and control groups. To further clarify the potential involvement of the variation at the DBH gene in schizophrenia we have studied the DBH (GT)(n) repeat in a sample of 47 Spanish schizophrenic patients, in their healthy relatives (n = 72), and in a control population (n = 74).

SRY gene transferred to the long arm of the X chromosome in a Y-positive XX true hermaphrodite.

Yp-specific sequences, including the testicular determinant gene SRY, have been detected and located in a 46,XX true hermaphrodite individual, using PCR amplification and fluorescent in situ hybridization (FISH). Among different Y chromosome loci tested, it was only possible to detect Yp sequences. The Y-centromere and Yq sequences were absent.

Dentatorubropallidoluysian atrophy in a spanish family: a clinical, radiological, pathological, and genetic study.

Unlabelled: The object was to describe the clinical, radiological, pathological, and genetic findings in a Spanish family with dentatorubropallidoluysian atrophy (DRPLA). This is an inherited neurodegenerative disease, well recognised in Japan, but with few cases reported from Europe and America and no cases published from Spain. The clinical misdiagnosis of Huntington's disease is not infrequent.

[Clinical characterization, molecular and FISH studies in 80 patients with clinical suspicion of Williams-Beuren syndrome].

Background: Williams-Beuren syndrome is a developmental disorder affecting vascular and connective tissues and central nervous system. The syndrome is caused by a submicroscopic deletion in the chromosome 7 implicating the 7q11.23 region.

Trisomy/tetrasomy 21 mosaicism in CVS: interpretation of cytogenetic discrepancies between placental and fetal chromosome complements.

Trisomy/tetrasomy 21 mosaicism was found in chorionic villi (semidirect preparation) obtained from a 40 year old pregnant woman. Since both cell lines were abnormal, the couple elected for pregnancy termination. Placenta and fetal tissue samples were obtained for cytogenetic study.

Parental origin and meiotic stage of non-disjunction in 139 cases of trisomy 21.

The parental origin and the meiotic stage of non-disjunction have been determined in 139 Down syndrome patients with regular trisomy 21 and in their parents through the analysis of DNA polymorphism. The meiotic error is maternal in 91.60% cases and paternal in 8.

Assaying the granulocyte-macrophage colony-stimulating factor (GM-CSF) as a mitogen of immature cells in fetal blood cultures.

Based on the presence of immature cells in fetal blood, and in an attempt to shorten the cytogenetic reporting time, three simultaneous one-day culture regimes were established in 23 fetal blood samples: (a) the standard phytohemagglutinin (PHA)-stimulated lymphocytes culture, (b) a culture using the granulocyte-macrophage colony-stimulating factor (GM-CSF) as an alternative mitogen, and (c) an unstimulated culture. Diagnostic success rates achieved by these three methods were as follows: 43 per cent (95 per cent CI: 23-64) (GM-CSF), 30 per cent (95 per cent CI: 12-49) (PHA) and 9 per cent (unstimulated). These three regimes were also assayed in three-day cultures giving 100 per cent diagnostic success rate for the PHA and GM-CSF, and 62 per cent (95 per cent CI: 41-83) for the unstimulated.

A presenilin 1 mutation (Ser169Pro) associated with early-onset AD and myoclonic seizures.

Objective: To characterize the mutation responsible for early-onset AD in a large Spanish kindred.

Background: Mutations in the presenilin 1 (PS1) gene have been identified and are known to be responsible for 18 to 50% of familial early-onset AD cases.

Methods: Patients were characterized clinically.

Alpha1-antichymotrypsin gene polymorphism and susceptibility to Parkinson's disease.

Objective: To determine whether the alpha1-antichymotrypsin AA genotype (ACT-AA) confers susceptibility for developing Parkinson's disease (PD) in the Spanish population.

Background: A correlation between the ACT-AA genotype and the risk of developing PD has been recently reported in the Japanese population.

Methods: The ACT genotypes of 71 patients diagnosed with clinically definite PD were compared with those of 109 age-matched healthy control subjects.

Prevalence of the Cys282Tyr and His63Asp HFE gene mutations in Spanish patients with hereditary hemochromatosis and in controls.

Background/aims: A mutation (Cys282Tyr) of the HFE gene has recently been reported to be present in most of the patients with hereditary hemochromatosis of Northern European ancestry, but in a lower frequency in Italy. No data are so far available on the prevalence of these mutations in Spain. Therefore, we initiated the present study to determine if the reported Cys282Tyr HFE mutation is also the main cause of hereditary hemochromatosis in Spain.

Prevalence of Y chromosome microdeletions in oligospermic and azoospermic candidates for intracytoplasmic sperm injection.

Objective: To determine the prevalence and type of Y chromosome microdeletions in 136 consecutively seen intracytoplasmic sperm injection (ICSI) candidates and in 50 consecutively seen azoospermic men attending an infertility clinic.

Design: Controlled clinical study.

Setting: Genetics laboratory and infertility clinic at a University hospital.

Molecular, cytogenetic, and clinical characterisation of six XX males including one prenatal diagnosis.

Cytogenetic analysis, fluorescent in situ hybridisation (FISH), and molecular amplification have been used to characterise the transfer of Yp fragments to Xp22.3 in six XX males. PCR amplification of the genes SRY, RPS4Y, ZFY, AMELY, KALY, and DAZ and of several other markers along the Y chromosome short and long arms indicated the presence of two different breakpoints in the Y fragment.

Significant changes in the tau A0 and A3 alleles in progressive supranuclear palsy and improved genotyping by silver detection.

Background: Progressive supranuclear palsy (PSP) is characterized by intraneuronal inclusions of neurofibrillary tangles formed by aggregated tau protein. A significant association between the tau gene A0/A0 genotype and PSP recently has been reported.

Objectives: To determine if a significant association between the tau gene A0/A0 genotype and PSP could be found in an independent population with a genetic background different from that in which the initial association was reported, and to standardize a nonradioactive method for tau gene genotyping.

Cytogenetic studies in fetal blood.

In order to assess the effectiveness and reliability of cytogenetic diagnosis provided by fetal blood, we report the first 186 cases of fetal blood sampling performed for rapid karyotype between 19-37 weeks of pregnancy in our Prenatal Diagnosis Unit. The overall diagnostic success rate was 98%, achieving 100% in the last period of the study. Chromosomal anomalies were detected in 16% (29/182) of the fetuses.

[Genetics and allergy].

Complex diseases, including diseases of allergic origin (asthma, rhinitis, dermatitis), tend to cluster in families, suggesting the existence of a genetic predisposition that has been confirmed by the family and twin studies. However, it is difficult to establish a clear Mendelian pattern of inheritance and it is accepted that multiple genes exist which have an additive effect (polygeny) and interact with environmental factors (multifactorial polygenic mechanism) to cause not only the atopic constitution but also the pathology that derives from it. Advances in genetics and molecular biology, through linkage studies in chosen family nuclei and different population groups, are facilitating the location of chromosomal regions related with allergic pathology.

Apolipoprotein E epsilon 4 alleles and meiotic origin of non-disjunction in Down syndrome children and in their corresponding fathers and mothers.

An increased risk of Alzheimer disease (AD) has been reported in young mothers of Down syndrome (DS) probands. Subsequently, an increased frequency of the apolipoprotein E (apoE) allele epsilon 4 has been found in mothers (< or = 32 years) of DS children due to meiosis II (MII) errors providing a potential explanation for the increased risk of AD in DS mothers. In the present study we genotyped apoE and determined the origin of non-disjunction of 132 mothers and the corresponding fathers and DS children from Spain.