Challenges in genetic diagnosis, co-occurrence of 22q11.2 deletion syndrome and Noonan syndrome.

Noonan syndrome (NS) is caused by pathogenic variants in genes involved in the RAS/MAPK pathway. On the other hand, 22q11.2 Deletion Syndrome (22q11.

Noonan syndrome with loose anagen hair with variants in the PPP1CB gene: First familial case reported.

Rasopathies are a group of phenotypically overlapping conditions that include Noonan, Noonan with multiple lentigines, Noonan with loose anagen hair, Costello, Cardio-facio-cutaneous, and Neurofibromatosis-Noonan syndromes. Noonan syndrome with loose anagen hair (NS-LAH) is clinically characterized by prominent forehead, macrocephaly, growth hormone deficiency, sparse, loose and slow-growing anagen hair, hyperpigmented skin with eczema or ichthyosis, mild psychomotor delays, hypernasal voices, and attention deficit hyperactivity disorder. Variants in SHOC2 are responsible for the majority of the cases.

Molecular analysis of gene in Argentinian population: Correlation with enzyme activity and characterization of a novel Duarte-like allele.

Background: Classical galactosemia is an autosomal recessive inherited metabolic disorder caused by mutations in the galactose-1-phosphate uridyltransferase () gene. GALT enzyme deficiency leads to the accumulation of galactose-1-phosphate in various organs, causing hepatic, renal and cerebral impairment. Over 300 mutations have been reported in the gene.

Providing more evidence on LZTR1 variants in Noonan syndrome patients.

Noonan syndrome (NS, OMIM 163950) is a common autosomal dominant RASopathy caused mainly by gain-of-function germline pathogenic variants in genes involved in the RAS/MAPK signaling pathway. LZTR1 gene has been associated with both dominant and recessive NS. Here, we present seven patients with NS and variants in the LZTR1 gene from seven unrelated families, 14 individuals in total.

Population pharmacokinetics of amikacin in patients with pediatric cystic fibrosis.

Introduction: Amikacin is commonly used in patients with pediatric cystic fibrosis (CF) for the treatment of pulmonary exacerbations. Amikacin efficacy is related to maximum plasma concentration/minimum inhibitory concentration (Cmax/MIC) ratio >8. Pharmacokinetic data in patients with pediatric CF are scarce.

Genotype-phenotype correlation of SMN locus genes in spinal muscular atrophy children from Argentina.

Background/purpose: Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder, considered one of the leading causes of infant mortality. It is caused by mutations in the SMN1 gene. A highly homologous copy of this gene named SMN2 and other neighbouring genes, SERF1A and NAIP, are considered phenotypic modifiers of the disease.

Mannose-binding lectin gene as a modifier of the cystic fibrosis phenotype in Argentinean pediatric patients.

Background: There is a considerable variation in the phenotype and course of the disease in cystic fibrosis (CF) even in patients with the same CFTR genotype, suggesting that other factors are important for prognosis. Mannose-binding lectin (MBL) has been proposed as one of these factors. We therefore investigated the influence of MBL2 gene variants on disease severity, age at acquisition of Pseudomonas aeruginosa, and survival in CF patients.

Influence of β(2)-adrenergic receptor polymorphisms on asthma exacerbation in children with severe asthma regularly receiving salmeterol.

Background: New evidence suggests that different β(2)-adrenergic receptor (β2AR) polymorphisms may influence asthma control in patients receiving long-acting β(2)agonists (LABAs) as regular therapy.

Objectives: To determine the influence of β2AR polymorphisms on asthma exacerbations in children with severe asthma from Argentina receiving inhaled corticosteroid (ICS) and LABAs regularly.

Methods: Ninety-seven children with severe asthma were genotyped for polymorphisms of β2AR at codons 16 and 27.

Prevalence of DFNB1 mutations in Argentinean children with non-syndromic deafness. Report of a novel mutation in GJB2.

Objective: Mutations in DFNB1 locus, containing GJB2 (connexin 26) and GJB6 (connexin 30) genes, are the most common cause of autosomal recessive non-syndromic hearing loss. More than 100 mutations in GJB2 have been reported worldwide. Two deletions in GJB6, del(GJB6-D13S1830) and del(GJB6-D13S1854), have been found to be frequent in the Spanish population.

Beta 2-adrenergic polymorphisms and total serum IgE levels in children with asthma from Argentina.

Background: Beta 2-Adrenergic receptor polymorphisms occurring at amino acid positions 16 (arginine/glycine) and 27 (glutamine/glutamic acid) are known to be functionally relevant. Associations with several asthma-related phenotypes, such as total serum IgE, have been investigated with different results.

Objective: To determine the contribution of polymorphisms and haplotypes of beta 2-adrenergic receptor with serum IgE levels in children from Argentina with mild, moderate, and severe asthma.

Influence of beta2-adrenoceptor polymorphisms on the response to chronic use of albuterol in asthmatic children.

Background: Several studies have suggested that after regular use of short acting beta2-agonists the bronchodilator effect of the drug may decline and this condition would be related to polymorphisms of the beta2-adrenergic receptor (beta2-AR).

Objective: To assess the frequency of beta2-AR polymorphisms in asthmatic children from Argentina, and to evaluate their influence on bronchodilator desensitization to albuterol over a 4-week treatment.

Methods: beta2-AR genotypes were determined in 117 children with asthma and 101 of them were under 4 weeks treatment with albuterol.

Carrier frequency of the 35delG and A1555G deafness mutations in the Argentinean population. Impact on the newborn hearing screening.

Objective: Hearing loss is a complex multifactorial disorder caused by genetic and environmental factors. The 35delG mutation in the GJB2 gene is the most prevalent mutation in Caucasian patients with genetic sensorineural deafness. The A1555G mutation in the mitochondrial 12S rRNA is the main genetic alteration associated with aminoglycoside-induced deafness.

High specificity of head circumference to recognize N540K mutation in hypochondroplasia.

Hypochondroplasia (HCH) is a skeletal dysplasia characterized by short stature with disproportionately short arms and legs. Anthopometrics and skeletal features are very similar to achondroplasia but milder. Seventy per cent of affected individuals are heterozygous for a mutation of the FGFR3 gene.