Coping strategies and postpartum depressive symptoms: A structural equation modelling approach.

BACKGROUND: Variables such as the mother's personality, social support, coping strategies and stressful events have been described as risk factors for postpartum depression. Structural Equation Modelling (SEM) analysis was used to examine whether neuroticism, perceived social support, perceived life events, and coping strategies are associated with postpartum depressive symptoms at the 8th and 32nd weeks. METHODS: A total of 1626 pregnant women participated in a longitudinal study. Different evaluations were performed 8 and 32weeks after delivery. Several measures were used: the Edinburgh Postnatal Depression Scale (EPDS), the Diagnostic Interview for Genetic Studies (DIGS), the Eysenck Personality Questionnaire (EPQ-RS), the St. Paul Ramsey life events scale and the Duke-UNC Functional Social Support Questionnaire. The brief COPE scale was used to measure coping strategies. SEM analysis was conducted for all women and in those women with a clinical diagnosis of postpartum depression. RESULTS: Passive coping strategies were associated with postpartum depressive symptoms at both visits (8th and 32nd weeks). Neuroticism was associated with more passive coping strategies and less active coping strategies. Neuroticism and life stress were positively correlated, and social support was negatively correlated with life stress and neuroticism. CONCLUSIONS: Early identification of potential risk for symptomatology of depression postpartum should include assessment of neuroticism, life events, social support and coping strategies.

[Autosomal recessive diseases with mental retardation]. / Enfermedades autosómicas recesivas con retraso mental.

INTRODUCTION: Autosomal recessive diseases with mental retardation are disorders that affect autosomes, and their genetic expression occurs in individuals who are homozygotic for a mutation, while heterozygotic subjects are unaffected carriers. If both parents are carriers, the theoretical possibility of their children also being carriers is 50%, the risk of the children being affected by the disease is 25%, and there is a 25% chance of their being healthy. They are an important source of mental deficiencies and inborn errors of metabolism (IEM) are some of their characteristic syndromes. DEVELOPMENT: The genetic disorders known as IEM can be classified according to the metabolism they affect, that is, purines, pyrimidines, amino acids, and so on. One of the lysosomal disorders is Tay-Sachs disease, which is rare among the general population but is very frequent in populations with a high rate of consanguinity, such as the Ashkenazi Jews. One of the most notable disorders affecting the metabolism of amino acids is the case of phenylketonuria due to mutations in the phenylalanine hydroxylase gene (PAH). It accounts for 0.5-1% of mental diseases and appears with a frequency rate of between 1/11,500 and 1/14,000 in newborn infants. Its early diagnosis through neonatal screening programmes makes it possible to start administering a phenylalanine-free diet and thus prevent mental retardation. CONCLUSIONS: Knowledge of this kind of autosomal diseases with neurological involvement, together with their correct and early diagnosis, makes it possible to establish suitable treatment regimens in some cases and to carry out genetic counselling in all of them.

[Experimental models used in research into genetic disorders that involve intellectual disability]. / Modelos experimentales utilizados en la investigación de trastornos genéticos que cursan con discapacidad intelectual.

INTRODUCTION: A basic principle of molecular and clinical medicine states that the function of the organs and the cells they are made up of is determined by the overall set of specific proteins. Therefore, the function of each organ depends on the molecules present in each cell, and hence it comes as no surprise to find that when tissue function is altered, different changes have taken place in the proteins. In the nervous system there are numerous examples of changes in proteins that correlate with functional alterations, either during normal or pathological development. DEVELOPMENT: In order to understand these relations, and to establish models in which to study the aetiopathogenesis of the disease, it is necessary to direct steady synthesis or to suppress synthesis in the brain of the protein that is potentially involved in the development of the disease. In consequence, it is possible to determine whether the presence or the absence of the protein is the direct or indirect cause of the effects; this is one of the main goals that must be achieved in order to enable researchers to define potential therapeutic targets in hereditary diseases. In order to manipulate the specific protein causing a pathology, we use experimental animal models as essential research tools, since they enable us to determine which mechanisms are altered and how the function of a particular protein affects the mechanisms being studied. CONCLUSIONS: Suppressing a gene or its over-expression in models using genetically modified mice will provide us with a means of modifying the genome and, eventually, the protein in the different tissues as well as in the nervous system in an attempt to imitate the genetic pathology that involves mental retardation. By controlling or suppressing the expression of a protein in the brain it becomes possible to remodel the functional profile of the tissue and study the consequences of molecular genetic manipulation, together with the biochemical, cytological and physiological processes, under normal basal conditions and under specific stimuli or conditions such as stress.

[Large-scale genotyping in research into autism spectrum disorders and attention deficit hyperactivity disorder]. / Genotipado a gran escala en la investigación del trastorno del espectro autista y el trastorno por deficit de atención con hiperactividad.

INTRODUCTION AND DEVELOPMENT: Autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) are two neuropsychiatric disorders beginning in childhood that present a high degree of familial aggregation. ASD is characterised by social interaction and communication disorders, whereas patients with ADHD display persistent inattention and/or hyperactive-impulsive behaviour. With the exception of a few cases of autism in which cytogenetic anomalies or mutations have been reported in specific genes, the aetiology of these diseases remains unknown. This is a group of multifactorial diseases with several genes having a lesser effect and there is also an environmental component. Genetic linkage studies have pointed to about 20 chromosomal regions that could well contain genes that grant susceptibility to autism, to ADHD or to both disorders. The challenge to researchers lies in the clinical characterisation, recruitment of patients with ASD and ADHD, gene dosage quantification studies, comparative genomic methylation and hybridisation in order to identify chromosomal rearrangements in patients with autism and severe mental retardation. CONCLUSIONS: Genotyping large SNP-type collections that are potentially functional in genes that are candidates for these disorders, based on pharmacological, biochemical and neuropathological data together with that coming from animal models and linkage studies in a wide collection of samples from patients and controls, will enable us to identify the genetic components of these pathologies and to define their biological foundations.

[Experimental therapeutic models for fragile X syndrome]. / Modelos terapéuticos experimentales en el síndrome X frágil.

Fragile X syndrome is the most frequent form of familial mental retardation. The disease is caused by the absence of the function of the FMR1 gene product (FMRP). FMRP is a mRNA binding protein but the mechanism by which FMRP inactivation leads to the cognitive deficits in fragile X patients is still unknown. There is no effective specific treatment for the disease. The genetics of the fragile X syndrome suggest that gene therapy may eventually be able to provide a cure for the disease. However several different approaches are also being investigated by many different research laboratories. The search for an effective therapy for fragile X patients will be facilitated by a better understanding of the pathophysiology of the disease. This requires research into many different areas of biology including protein replacement therapy, gene reactivation, transcriptional regulation, neuronal activity enhancement and neuroprotection, nutritional intervention, regulation of neurotransmission and synapse regeneration. All these approaches can be investigated using animal models of the fragile X syndrome, before being used to develop effective treatment for fragile X patients. Although there is still no cure for the fragile X syndrome, the symptoms of the disease can be treated using an integrated approach where the different interventions are supported by a specific team. All of these approaches are providing new insights into both the treatment of fragile X patients and our understanding of the pathophysiology of the disease. Until a cure is found, an integrated approach to intervention is the best way to minimise or avoid some of the manifestations associated with the fragile X syndrome.

Twin sisters, monozygotic with the fragile X mutation, but with a different phenotype.

The absence of the fragile X mental retardation protein (FMRP) results in fragile X syndrome. All males with a full mutation in the FMR1 gene and an inactive FMR1 gene are mentally retarded while 60% of the females with a full mutation are affected. Here we describe monozygotic twin sisters who both have a full mutation in their FMR1 gene, one of whom is normal while the other is affected. Using molecular and protein studies it was shown that owing to preferential X inactivation in the affected female a minority of the cells expressed the normal FMR1 gene, while in her sister most cells expressed the normal FMR1 gene. This shows that X inactivation took place in the female twins after separation of the embryos and that for a normal phenotype FMR1 expression is necessary in the majority of cells.

Immunocytochemical and biochemical characterization of FMRP, FXR1P, and FXR2P in the mouse.

Fragile X syndrome is caused by the absence of expression of the FMR1 gene. Both FXR1 and FXR2 are autosomal gene homologues of FMR1. The products of the three genes are belonging to a family of RNA-binding proteins, called FMRP, FXR1P, and FXR2P, respectively, and are associated with polyribosomes as cytoplasmic mRNP particles. The aim of the present study is to obtain more knowledge about the cellular function of the three proteins (Fxr proteins) and their interrelationships in vivo. We have utilized monospecific antibodies raised against each of these proteins and performed Western blotting and immunolabeling at the light-microscopic level on tissues of wild-type and Fmr1 knockout adult mice. In addition, we have performed immunoelectron microscopy on hippocampal neurons of wild-type mice to study the subcellular distribution of the Fxr proteins. A high expression was found in brain and gonads for all three proteins. Skeletal muscle tissue showed only a high expression for Fxr1p. In the brain the three proteins were colocalized in the cytoplasm of the neurons; however, in specific neurons Fxr1p was also found in the nucleolus. Immunoelectronmicrsocopy on hippocampal neurons demonstrated the majority of the three proteins in association with ribosomes and a minority in the nucleus. The colocalization of the Fxr proteins in neurons is consistent with similar cellular functions in those specific cells. The presence of the three proteins in the nucleus of hippocampal neurons suggests a nucleocytoplasmic shuttling for the Fxr proteins. In maturing and adult testis a differential expression was observed for the three proteins in the spermatogenic cells. The similarities and differences between the distribution of the Fxr proteins have implications with respect to their normal function and the pathogenesis of the fragile X syndrome.

Noninvasive test for fragile X syndrome, using hair root analysis.

Identification of the FMR1 gene and the repeat-amplification mechanism causing fragile X syndrome led to development of reliable DNA-based diagnostic methods, including Southern blot hybridization and PCR. Both methods are performed on DNA isolated from peripheral blood cells and measure the repeat size in FMR1. Using an immunocytochemical technique on blood smears, we recently developed a novel test for identification of patients with fragile X syndrome. This method, also called "antibody test," uses monoclonal antibodies against the FMR1 gene product (FMRP) and is based on absence of FMRP in patients' cells. Here we describe a new diagnostic test to identify male patients with fragile X syndrome, on the basis of lack of FMRP in their hair roots. Expression of FMRP in hair roots was studied by use of an FMRP-specific antibody test, and the percentage of FMRP-expressing hair roots in controls and in male fragile X patients was determined. Control individuals showed clear expression of FMRP in nearly every hair root, whereas male fragile X patients lacked expression of FMRP in almost all their hair roots. Mentally retarded female patients with a full mutation showed FMRP expression in only some of their hair roots (<55%), and no overlap with normal female controls was observed. The advantages of this test are (1) plucking of hair follicles does no appreciable harm to the mentally retarded patient, (2) hairs can be sent in a simple envelope to a diagnostic center, and (3) the result of the test is available within 5 h of plucking. In addition, this test enabled us to identify two fragile X patients who did not show the full mutation by analysis of DNA isolated from blood cells.