[Nager syndrome associated with tetralogy of Fallot: A frequent association?]

Nager syndrome belongs to a heterogeneous group of disorders involving abnormal development of the extremities, face, and jaw: acrofacial dysostosis (AFD). Fewer than 100 cases of Nager syndrome have been reported to date. Recently, mutations in the 1q21.2 region of the SF3B4 gene (splicing factor 3B subunit 4), which encodes a spliceosomal protein (SAP49) involved in the assembly of the spliceosomal complex U2SNP, have been demonstrated in patients with Nager syndrome. We report the case of a child who had a characteristic association (Pierre Robin sequence, bilateral and symmetrical malar hypoplasia, absent thumbs) clinically diagnosed as Nager syndrome. This child also presented tetralogy of Fallot. This combination is unusual; only two other cases have been described. The karyotype and the CGH-array were normal. After the description in 2012 of several mutations in the SF3B4 gene (1q21.2) in Nager syndrome, a genetic search for our patient revealed the mutation c.1229delC. In 2013, other authors showed the presence of these same mutations in the majority of their patients diagnosed as Nager syndrome. The haploinsufficiency of the SF3B4 region seems to be the major cause of Nager syndrome.

[Verapamil intoxication: beware of the delayed effect]

Intoxication with calcium channel inhibitory drugs is rare but mortality rates reach 10 %. We report the case of a 5-year-old girl who had ingested five 240-mg tablets of extended-release verapamil (VLP) and a tablet of bromazepam. Thirty hours after the ingestion she had a vasoplegic shock, heart conduction disorders, and metabolic complications. She was treated in pediatric intensive care with continuous epinephrine and insulin and recovered completely 60h after the ingestion. This case underlines the danger of calcium channel blocker overdose, increased by the extended-release mechanism: the drug effect is to slow down gastric motility - which explains the latency of the symptoms - but this also increases the drug absorption, inducing a vicious circle. These mechanisms in calcium blocker intoxication need to be kept in mind in order to decrease the mortality of such accidents.

Childhood myocarditis and parvovirus B19 genotypes

BACKGROUND

Human parvovirus B19 (PVB19) infection is occasionally associated with acute myocarditis. Three cases of children with PVB19 virus-associated myocarditis occurred in a very short period and the same geographical region.

OBJECTIVE

To elucidate if virological factors could be responsible for determining the course of infection, a molecular epidemiologic investigation was performed.

STUDY DESIGN

The diagnosis of myocarditis was established by histology or echocardiography. In the three cases, the PVB19 DNA was detected in different samples. Eight different regions were amplified by PCR using a high fidelity Taq polymerase and sequenced on both strands. Phylogenetic analyses were performed. First, the genotypes of the PVB19 strains were determined, then the intra-patient viral variability was analysed by sequencing PVB19 detected in different specimens sampled from the same patient at the same moment.

RESULTS

Nearly complete sequences of the PVB19 virus (4265nt) were obtained from different samples in the three patients. The phylogenetic analyses showed that PVB19 strains identified clustered with genotype 1a PVB19 strains referenced in GenBank. When compared to the referenced strain NC_000883, the number of substitutions (transitions and transversions) were as follows: 58 for Caen.FRA/19.09, 74 for Caen.FRA/21.09 and 60 for Caen.FRA/24.09. The strains isolated from the same patient showed 100% of similarity.

CONCLUSIONS

Viral myocarditis is a frequently unrecognized cause of post-inflammatory cardiomyopathy. The detailed molecular analyses do not give rise to virological markers associated with myocarditis in these children.