Genetics of cardiological disorders

Outcome of arterial ischemic stroke in children with heart disease

Arterial ischemic strokes (AIS) are rare in childhood. Congenital and acquired heart diseases are one of the most important risk factors of AIS in children.

OBJECTIVE

Study the outcome of children with heart disease that have suffered AIS and the factors that influence on prognosis.

PATIENTS AND METHODS

We evaluated all children with heart disease who had suffered AIS between 2000 and 2014 in our hospital.

RESULTS

Seventy-four children with heart disease suffered an arterial ischemic stroke. 20% of them died and 10% had new AIS during the study period. Fifty-two patients were evaluated an average of six years after AIS. According to the Paediatric Stroke Outcome Scale (PSOM), most of the patients had some degree of impairment, mainly in sensorimotor and in cognitive-behavioural areas. The modified Rankin scale (mRS) showed an unfavourable outcome in 70% of patients (including patients that have died). Upper limb was more functionally impaired than lower limb. Strokes in neonatal period and early life were associated with poor prognosis. Size of stroke, cortical and subcortical involvement and basal ganglia stroke were associated with an unfavourable outcome. Fever in the acute phase and hemiparesis at presentation were also poor prognostic factors. Epilepsy at time of evaluation was also associated with unfavourable outcome. On the other hand, a normal electroencephalogram was associated with favourable outcome.

CONCLUSIONS

AIS in children with heart disease had an unfavourable outcome, with impairment in different areas. Epilepsy happened in one third of the patients.

Congenital heart disease and chromossomopathies detected by the karyotype

OBJECTIVE:

To review the relationship between congenital heart defects and chromosomal abnormalities detected by the karyotype.

DATA SOURCES:

Scientific articles were searched in MEDLINE database, using the descriptors "karyotype" OR "chromosomal" OR "chromosome" AND "heart defects, congenital". The research was limited to articles published in English from 1980 on.

DATA SYNTHESIS:

Congenital heart disease is characterized by an etiologically heterogeneous and not well understood group of lesions. Several researchers have evaluated the presence of chromosomal abnormalities detected by the karyotype in patients with congenital heart disease. However, most of the articles were retrospective studies developed in Europe and only some of the studied patients had a karyotype exam. In this review, only one study was conducted in Latin America, in Brazil. It is known that chromosomal abnormalities are frequent, being present in about one in every ten patients with congenital heart disease. Among the karyotype alterations in these patients, the most important is the trisomy 21 (Down syndrome). These patients often have associated extra-cardiac malformations, with a higher risk of morbidity and mortality, which makes heart surgery even more risky.

CONCLUSIONS:

Despite all the progress made in recent decades in the field of cytogenetic, the karyotype remains an essential tool in order to evaluate patients with congenital heart disease. The detailed dysmorphological physical examination is of great importance to indicate the need of a karyotype.

Clinical and molecular characterisation of Holt-Oram syndrome focusing on cardiac manifestations

BACKGROUND

Holt-Oram syndrome is characterised by CHD and limb anomalies. Mutations in TBX5 gene, encoding the T-box transcription factor, are responsible for the development of Holt-Oram syndrome, but such mutations are variably detected in 30-75% of patients.

METHODS

Clinically diagnosed eight Holt-Oram syndrome patients from six families were evaluated the clinical characteristics, focusing on the cardiac manifestations, in particular, and molecular aetiologies. In addition to the investigation of the mutation of TBX5, SALL4, NKX2.5, and GATA4 genes, which are known to regulate cardiac development by physically and functionally interacting with TBX5, were also analyzed. Multiple ligation-dependent probe amplification analysis was performed to detect exonic deletion and duplication mutations in these genes.

RESULTS

All included patients showed cardiac septal defects and upper-limb anomalies. Of the eight patients, seven underwent cardiac surgery, and four suffered from conduction abnormalities such as severe sinus bradycardia and complete atrioventricular block. Although our patients showed typical clinical findings of Holt-Oram syndrome, only three distinct TBX5 mutations were detected in three families: one nonsense, one splicing, and one missense mutation. No new mutations were identified by testing SALL4, NKX2.5, and GATA4 genes.

CONCLUSIONS

All Holt-Oram syndrome patients in this study showed cardiac septal anomalies. Half of them showed TBX5 gene mutations. To understand the genetic causes for inherited CHD such as Holt-Oram syndrome is helpful to take care of the patients and their families. Further efforts with large-scale genomic research are required to identify genes responsible for cardiac manifestations or genotype-phenotype relation in Holt-Oram syndrome.

Cardiovascular genetic medicine: evolving concepts, rationale, and implementation

Cardiovascular genetic medicine is devoted to the identification and understanding of cardiac conditions resulting from genetic and genomic mechanisms and to the development and validation of diagnostic and treatment algorithms and guidelines. Cardiovascular genetic medicine clinics now provide expert cardiovascular subspecialty care, genetic counseling and clinical genetic testing, and will eventually provide disease-specific gene or genetic therapies. Currently, the most tractable diagnoses for cardiovascular genetic medicine are the single-gene disorders: the cardiomyopathies, the channelopathies, and others. The recent explosion of genetic knowledge within the single-gene disorders and consequent rapid proliferation of genetic testing enables far greater numbers of individuals to directly benefit from this progress. A compelling rationale exists for this approach: cardiovascular single-gene diseases commonly present with life-threatening events (e.g., sudden cardiac death, heart failure, stroke, etc.), but identification, evaluation, and treatment of individuals with presymptomatic genetic risk has the promise to prevent or ameliorate cardiovascular morbidity and mortality. Cardiovascular genetic medicine programs also anchor training and research, thereby enabling the next generation of academic specialists in cardiovascular genetic medicine to continue to improve cardiovascular health.