Familial transposition of the great arteries caused by multiple mutations in laterality genes.

Background: The pathogenesis of transposition of the great arteries (TGA) is still largely unknown. In general, TGA is not associated with the more common genetic disorders nor with extracardiac anomalies, whereas it can be found in individuals with lateralisation defects, heterotaxy and asplenia syndrome (right isomerism).

Objective: To analyse genes previously associated with heterotaxy in order to assess mutations in familial TGA unassociated with other features of laterality defects.

Three patients with oculo-auriculo-vertebral spectrum and microdeletion 22q11.2.

We report on three unrelated patients with the 22q11.2 microdeletion syndrome (del22q11) who have phenotypic anomalies compatible with oculo-auriculo-vertebral spectrum (OAVS). Hemifacial microsomia, unilateral microtia, hearing loss, congenital heart/aortic arch arteries defects, and feeding difficulties were present in all three patients.

Identification and characterization of seven novel mutations of elastin gene in a cohort of patients affected by supravalvular aortic stenosis.

Supravalvular aortic stenosis (SVAS) is a congenital narrowing of the ascending aorta, which can occur sporadically as an autosomal dominant condition or as one component of the Williams-Beuren syndrome, a complex developmental genomic disorder associated with cardiovascular, neurobehavioral, craniofacial, and metabolic abnormalities, caused by a microdeletion at 7q11.23. We report the identification of seven novel mutations within the elastin gene in 31 familial and sporadic cases of nonsyndromic SVAS.

High-resolution SNP arrays in mental retardation diagnostics: how much do we gain?

We used Affymetrix 6.0 GeneChip SNP arrays to characterize copy number variations (CNVs) in a cohort of 70 patients previously characterized on lower-density oligonucleotide arrays affected by idiopathic mental retardation and dysmorphic features. The SNP array platform includes approximately 900,000 SNP probes and 900,000 non-SNP oligonucleotide probes at an average distance of 0.

Mild ring 17 syndrome shares common phenotypic features irrespective of the chromosomal breakpoints location.

Ring 17 syndrome is a rare disorder with clinical features influenced by the presence or deletion of the Miller-Dieker critical region (MDCR). Presence of the MDCR is associated with a mild phenotype, including growth delay (GD), mental retardation (MR), seizures, cafè au lait skin (CALS) spots and minor facial dysmorphisms. Previous studies have been mainly focused on this locus providing poor information about the role of other genes located on the p- and q-arms.

Impact of DEL22q11, trisomy 21, and other genetic syndromes on surgical outcome of conotruncal heart defects.

Objective: Genetic syndromes occur in more than 20% of patients with conotruncal heart defects. We investigated the impact of genetic syndromes on the surgical outcome of conotruncal anomalies in infancy.

Methods: This retrospective study reviews the outcome of 787 patients (median age 6.

Mutation of SHOC2 promotes aberrant protein N-myristoylation and causes Noonan-like syndrome with loose anagen hair.

N-myristoylation is a common form of co-translational protein fatty acylation resulting from the attachment of myristate to a required N-terminal glycine residue. We show that aberrantly acquired N-myristoylation of SHOC2, a leucine-rich repeat-containing protein that positively modulates RAS-MAPK signal flow, underlies a clinically distinctive condition of the neuro-cardio-facial-cutaneous disorders family. Twenty-five subjects with a relatively consistent phenotype previously termed Noonan-like syndrome with loose anagen hair (MIM607721) shared the 4A>G missense change in SHOC2 (producing an S2G amino acid substitution) that introduces an N-myristoylation site, resulting in aberrant targeting of SHOC2 to the plasma membrane and impaired translocation to the nucleus upon growth factor stimulation.

3q29 Microdeletion: a mental retardation disorder unassociated with a recognizable phenotype in two mother-daughter pairs.

The 3q29 microdeletion syndrome (del 3q29) is a novel genomic disorder identified after the introduction of microarray-based technology. The phenotype of the reported patients is variable, including mental retardation and subtle facial anomalies. We report on two mother-daughter pairs, heterozygous for 3q29, and review clinical features of all known affected individuals.

Confirmation of microcephaly-facio-cardio-skeletal Hadziselimovic type syndrome.

Three patients are reported, including two dizygotic twins born to consanguineous parents, presenting with a disorder characterized by growth retardation, microcephaly, distinct facial features with hypotelorism, with or without epicanthic folds, prominent lips, low set ears, tetralogy of Fallot in two cases, short first metacarpals and thumbs, and hypoplastic radius and ulna in one patient. These features overlap those previously reported in two male siblings and suggest that this association of microcephaly-facio-cardio-skeletal defects could represent a unique autosomal or X-linked recessive disorder.

Exclusion of Cx43 gene mutation as a major cause of criss-cross heart anomaly in man.

Criss-cross heart is a rare congenital cardiac defect characterized by crossing of the atrioventricular valves and of the inflow streams due to the twisting of the ventricles about their long axis. The aetiology of criss-cross heart has not been understood yet. Mice homozygous for Cx43 deficiency show a delay in normal looping of ascending limb of the heart tube, which temporarily retains a more symmetric middle position.

16p subtelomeric duplication: a clinically recognizable syndrome.

We report on two patients with duplication of the subterminal region of chromosome 16p (dup16p) recognized by fluorescent in situ hybridization (FISH) telomere analysis, presenting with closely overlapping facial features and neurological impairment. Distinct facial anomalies included high forehead, sparse eyebrows, blepharophimosis, short nose, everted upper lip, high-arched palate, wide-spaced teeth, and cupped anteverted ears. Susceptibility to vascular anomalies, in particular pulmonary hypertension and portal cavernoma, was found in one patient.

Germline BRAF mutations in Noonan, LEOPARD, and cardiofaciocutaneous syndromes: molecular diversity and associated phenotypic spectrum.

Noonan, LEOPARD, and cardiofaciocutaneous syndromes (NS, LS, and CFCS) are developmental disorders with overlapping features including distinctive facial dysmorphia, reduced growth, cardiac defects, skeletal and ectodermal anomalies, and variable cognitive deficits. Dysregulated RAS-mitogen-activated protein kinase (MAPK) signal traffic has been established to represent the molecular pathogenic cause underlying these conditions. To investigate the phenotypic spectrum and molecular diversity of germline mutations affecting BRAF, which encodes a serine/threonine kinase functioning as a RAS effector frequently mutated in CFCS, subjects with a diagnosis of NS (N=270), LS (N=6), and CFCS (N=33), and no mutation in PTPN11, SOS1, KRAS, RAF1, MEK1, or MEK2, were screened for the entire coding sequence of the gene.

Spectrum of MEK1 and MEK2 gene mutations in cardio-facio-cutaneous syndrome and genotype-phenotype correlations.

Cardio-facio-cutaneous syndrome (CFCS) is a rare disease characterized by mental retardation, facial dysmorphisms, ectodermal abnormalities, heart defects and developmental delay. CFCS is genetically heterogeneous and mutations in the KRAS, BRAF, MAP2K1 (MEK1) and MAP2K2 (MEK2) genes, encoding for components of the RAS-mitogen activated protein kinase (MAPK) signaling pathway, have been identified in up to 90% of cases. Here we screened a cohort of 33 individuals with CFCS for MEK1 and MEK2 gene mutations to further explore their molecular spectrum in this disorder, and to analyze genotype-phenotype correlations.

Genetic syndromes and congenital heart defects: how is surgical management affected?

The population of neonates and children with congenital heart defects presents about a 30% prevalence of associated genetic syndrome or additional extracardiac anomalies and may show an increased risk of death or major complication at cardiac surgery. Since a well-defined pattern of combined cardiac and extracardiac anomalies may be found in relation to specific genetic defects, correct understanding of the genetic issues may help improving diagnosis, surgical approach and final outcome of these patients. Hereby we review the medical and surgical issues correlated to the genetic asset in patients with congenital heart defects and genetic syndromes, including trisomy 21, deletion 22q11, Noonan/LEOPARD, Turner, Marfan and Williams syndromes.

A standard echocardiographic and tissue Doppler study of morphological and functional findings in children with hypertrophic cardiomyopathy compared to those with left ventricular hypertrophy in the setting of Noonan and LEOPARD syndromes.

Background: Several clinical and echocardiographic studies describe morphological and functional findings in patients with hypertrophic cardiomyopathy. Less is known regarding morphological and functional characteristics of the left ventricular hypertrophy found in the setting of the Noonan and LEOPARD syndromes.

Objective: To compare non-invasively the morphological and functional findings potentially affecting symptoms and clinical outcome in children with hypertrophic cardiomyopathy as opposed to Noonan and LEOPARD syndromes.

Masked complex chromosome rearrangement in a child thought to have del(8qter) as the sole cytogenetic abnormality.

Cytogenetic analyses of constitutional diseases have disclosed several chromosomal rearrangements. At the molecular level, these rearrangements often result in the breakage of genes or alteration of genome architecture. Fluorescence in situ hybridization (FISH) and molecular investigations of a patient showing hypotonia and dysmorphic traits revealed a masked complex chromosome abnormality previously detected by G-banding as a simple 8qter deletion.

Cardiac defects and results of cardiac surgery in 22q11.2 deletion syndrome.

Specific types and subtypes of cardiac defects have been described in children with 22q11.2 deletion syndrome as well as in other genetic syndromes. The conotruncal heart defects occurring in patients with 22q11.

Congenital heart defects in patients with oculo-auriculo-vertebral spectrum (Goldenhar syndrome).

The oculo-auriculo-vertebral spectrum (OAVS) is a non-random association of microtia, hemifacial microsomia with mandibular hypoplasia, ocular epibulbar dermoid, and cervical vertebral malformations. Congenital heart defects (CHDs) have been reported in 5-58% of the patients. We analyze the frequency and anatomic features of CHD in a series of 87 patients with OAVS examined between January 1990 and February 2007 with normal chromosomes, ranging in age between 0.

Leopard syndrome.

LEOPARD syndrome (LS, OMIM 151100) is a rare multiple congenital anomalies condition, mainly characterized by skin, facial and cardiac anomalies. LEOPARD is an acronym for the major features of this disorder, including multiple Lentigines, ECG conduction abnormalities, Ocular hypertelorism, Pulmonic stenosis, Abnormal genitalia, Retardation of growth, and sensorineural Deafness. About 200 patients have been reported worldwide but the real incidence of LS has not been assessed.

Genotype-phenotype analysis and natural history of left ventricular hypertrophy in LEOPARD syndrome.

Because it is unclear whether the genotype may influence the clinical course in patients with LEOPARD syndrome (LS), we analyzed clinical and molecular predictors of adverse cardiac events in patients with left ventricular hypertrophy (LVH). A comprehensive cardiovascular evaluation, including baseline electrocardiogram, echocardiography, exercise test and 24 hr Holter monitoring at the time of clinical diagnosis and during follow-up was conducted on 24 patients referred to our departments. Phenotypical examination and diagnosis were performed by expert clinical geneticists.