Extreme Phenotypic Variability of -Related Disorders in Hearing Loss.

Hearing loss is the most common sensory defect in humans, affecting normal communication. In most cases, hearing loss is a multifactorial disorder caused by both genetic and environmental factors, but single-gene mutations can lead to syndromic or non-syndromic hearing loss. Monoallelic variants in , coding for gamma (γ)-actin, are associated with classical Baraitser-Winter Syndrome type 2 (BRWS2, nonsyndromic deafness, and a variety of clinical presentations not fitting the original BRWS2 description or nonsyndromic deafness.

Case report: Novel SIN3A loss-of-function variant as causative for hypogonadotropic hypogonadism in Witteveen-Kolk syndrome.

Pubertal delay can be due to hypogonadotropic hypogonadism (HH), which may occur in association with anosmia or hyposmia and is known as Kallmann syndrome (OMIM #308700). Recently, hypogonadotropic hypogonadism has been suggested to overlap with Witteveen-Kolk syndrome (WITKOS, OMIM #613406) associated with 15q24 microdeletions encompassing . Whether hypogonadotropic hypogonadism is due to haploinsufficiency of or any of the other eight genes present in 15q24 is not known.

[Genetics of neurodevelopmental disorders. Practical aspects].

Neurodevelopmental disorders (NDD) constitute a relevant group of pathologies, of childhood, with a biological basis and totally or partially genetic etiology. The recognition of the causal factors constitutes a challenge that has been perfected over the last decades, until obtaining an increasing diagnostic yield. The implementation of these technological advances can only be achieved through the formation of interdisciplinary work teams, which, following an orderly process, achieve a presumptive diagnosis, which is then certified using the techniques that for each of the cases are more profitable in terms of quality and cost.

Clinical Spectrum and Tumour Risk Analysis in Patients with Beckwith-Wiedemann Syndrome Due to Pathogenic Variants.

Beckwith-Wiedemann syndrome spectrum (BWSp) is an overgrowth disorder caused by imprinting or genetic alterations at the 11p15.5 locus. Clinical features include overgrowth, macroglossia, neonatal hypoglycaemia, omphalocele, hemihyperplasia, cleft palate, and increased neoplasm incidence.

[Epigenetic mechanisms involved in the genesis of autism].

Autism is a neurobiological developmental disorder characterized by poor social interaction and communication, narrow interests, and stereotyped behaviors. It has been associated with disorders of synaptogenesis and multiple etiologies. The identification of the epigenetic factors involved in the genesis of autism allows a better understanding of the molecular mechanisms involved.

A few challenges in mucopolysaccharidosis type I.

Here we describe the current challenges of mucopolysaccharidosis type I: the need for an adequate classification, establishing its relationship to therapeutic indications; an early diagnosis, from neonatal screening, its advantages and barriers, to clinical suspicion of severe and attenuated forms; spinal and eye disease care, from diagnosis to follow-up and treatment; allergic reactions caused by enzyme replacement therapy, their diagnosis and treatment. And lastly, transition to adult care.

[Genetic literacy and psychological adaptation in adolescents with genetic diseases].

Introduction: Living with a genetic condition is complex and may be limiting for the adolescent. This situation is considered a stress factor and risk factor for the mental health of both the patient and his family. Objective: To study the levels of psychological adaptation and genetic literacy in adolescents with genetic diseases residing in Argentina.

Ophthalmic genetics in South America.

South America comprises of heterogeneous topographies, populations, and health care systems. Therefore, it is not surprising to see differences among the countries regarding expertise, education, and practices of ophthalmic genetics for patients with rare eye diseases. Nevertheless, common challenges such as limited genetics training in medical schools and among ophthalmologists, scarcity of diagnostic tools for phenotyping, and expensive genetic testing not covered by the public healthcare systems, are seen in all of them.

[Osteoporosis-pseudoglioma Syndrome: a pediatric case of primary osteoporosis].

Osteoporosis should be considered in children with severe chronic diseases or in association with some genetic diseases that bear an increased risk of bone fragility. Primary osteoporosis is an entity in which emerging aetiologies are being recognized. Its association with congenital retinal folds should guide the diagnosis to the Osteoporosis-Pseudoglioma syndrome (OMIM 259770), a rare disease (prevalence of 1/2 000 000), caused by the loss of function of the protein LRP5 (low-density lipoprotein receptor-related protein 5) resulting in the alteration of the Wnt/β-catenin signalling pathway.

Aging and Autism: Understanding, Intervention and Proposals to Improve Quality of Life.

Background: The population with autism spectrum disorder (ASD) has been increasing and is currently estimated to be 1 in 58 births. The increased prevalence of ASD together with the lack of knowledge on the processes of aging in this population, the support needed at this stage of life, and the associated risk factors, have led to an urgent need for further research.

Methods: This study provides a review of the literature on social- and health-related conditions that may appear when persons with ASD grow old.

A homozygous mutation in the highly conserved Tyr60 of the mature IGF1 peptide broadens the spectrum of IGF1 deficiency.

Background: IGF1 is a key factor in fetal and postnatal growth. To date, only three homozygous IGF1 gene defects leading to complete or partial loss of IGF1 activity have been reported in three short patients born small for gestational age. We describe the fourth patient with severe short stature presenting a novel homozygous IGF1 gene mutation.

[Autism. Genetic and biological aspects].

Autism is a neurodevelopmental disorder characterized by commitment to social interaction and communication, associated with interests restricted and stereotyped behaviors with a high population prevalence, neurobiological bases and high heritability. Its etiology is heterogeneous, numerous genetic bases, environmental factors and epigenetic mechanisms have been recognized. Advances in molecular genetics, as well as epidemiological studies of large cohorts, have made it possible to identify specific medical entities, as well as genes and environmental factors partially or totally linked in their pathogenesis.

[Autistic regression: clinical and aetiological aspects].

Introduction: Autism spectrum disorders are neurodevelopmental dysfunctions that are characterised by deficits in social integration and communication, associated with restricted interests and stereotypic behaviour. A high percentage are related to language disorders, sensory dysfunctions, attention deficit disorder, bipolarity, intellectual disability or epilepsy, among other comorbidities. It is estimated that around 30% of children with autism, with typical early development, may present regression in the first years of life, which was already reported by Kanner in one of his original cases.

[Autism: the importance of dysmorphology in the identification of associated medical conditions].

Introduction: Autism spectrum disorders (ASD) are characterized by deficits in communication and social interaction, associated with restricted interests and stereotyped behaviors. Considered as a neurodepelopment disorders, they present a recognized neurobiological basis. Genetic causes as chromosomes abnormalities, or genetic defects are the most recognized etiologies, followed by the environmental factors.

[Autism in females: clinical, neurobiological and genetic aspects].

Autism spectrum disorders are more prevalent in males than in females, and the proportion can range from 1.4 to 1, depending on the samples that are analysed. The smaller difference has been related to those who also manifest an associated intellectual disability, and it is accepted that in those cases females are far more seriously affected.

[Therapeutic approaches in autism spectrum disorders].

Autistic spectrum disorders affect one out of every 68 persons, with a 4:1 dominance in males. Since they are dysfunctions rather than irreversible injuries to the central nervous system, which can be attributed to deficits in the neuronal networks and synaptogenesis and are modifiable thanks to the plasticity of the brain, starting therapy as early as possible is essential for more favourable progress. Very few treatments are backed by solid scientific evidence.

Terminal osseous dysplasia with pigmentary defects (TODPD) due to a recurrent filamin A (FLNA) mutation.

Terminal osseous dysplasia with pigmentary defects (TODPD) is an X-linked dominant syndrome with distal limb anomalies, pigmentary skin defects, digital fibromas, and generalized bone involvement due to a recurrent mutation in the filamin A (FLNA) gene. We here report the mutation c.5217G>A in FLNA in three families with TODPD and we found possible germline and somatic mosaicism in two out of the three families.

Identification of 17 novel mutations in 40 Argentinean unrelated families with mucopolysaccharidosis type II (Hunter syndrome).

Mucopolysaccharidosis type II (MPSII) is an X-linked lysosomal storage disorder caused by deficiency of the enzyme iduronate-2-sulfatase (IDS). The human gene is located in chromosome Xq28. This is the first report of genotype and phenotype characterization of 49 Hunter patients from 40 families of Argentina.

[Autism and epigenetics. A model of explanation for the understanding of the genesis in autism spectrum disorders].

Autism spectrum disorders are characterized by impairment of social integration and language development and restricted interests. Autism spectrum disorders manifest during childhood and may have a varying clinical expression over the years related to different therapeutic approaches, behavior-modifying drugs, and environmental factors, among others. So far, the genetic alterations identified are not sufficient to explain the genesis of all these processes, as many of the mutations found are also present in unaffected individuals.

[Genetic syndromes recognizable in the neonatal period].

The presence of a neonatal neurological lesion associated or not with dysmorphism or with a particular phenotype can be caused by a) prenatal infections (Group TORCH) toxic or teratotoxic agents (alcohol, cocain, antiepileptics, inhalants such as toluene, etc.), vascular defects or genetic anomalies; b) perinatal isquemic hypoxic lesions, infectious or metabolic disorders, etc. In this paper we analyze all entities of genetic origin neonatally recognizable by their phenotype which must be included in the differential diagnosis of all children neurologically compromised.

[Pervasive developmental disorders. Clinical and genetics aspects].

Pervasive developmental disorders (PDD) encompass a heterogeneous group of children with deficits of verbal and non-verbal language, social communication, and with a restricted repertoire of activities or repetitive behaviours. The frequency in general population is considered 27.5/10,000.