Het Jervell-Lange-Nielsen-syndroom: Klinische presentatie bij een zuigeling

The long QT syndrome is characterised by QT prolongation on the ECG causing ventricular arrhythmias leading to syncope and sudden death. The congenital long QT syndromes can be divided in two types, the Romano Ward syndrome and the Jervell and Lange-Nielsen syndrome (JLNS). The Romano Ward syndrome is generally inherited as an autosomal dominant trait with, besides the long QT interval, usually no other phenotypic abnormalities. The Jervell and Lange-Nielsen syndrome is a rare autosomal recessive syndrome. The syndrome is characterised by a profound QT prolongation in association with congenital bilateral sensorineuronal deafness. The Romano Ward syndrome is caused by heterozygous mutations in one of the eight LQTS genes (KCNQI, HERG, SCN5A, KCNEI, KCNE2, ANK2, KCNJ2 and CavI.2) coding for cardiac sodium, potassium and calcium ion channels. The Jervell and Lange-Nielsen syndrome is, on the other hand, caused by homozygous or compound heterozygous mutations in only two out of the eight LQTS genes, namely KCNQI and KCNEI, which encode for potassium channels in the heart and the cochlea of the inner ear. Absence of the potassium channels results in both arrhythmias and a decrease of the potassium levels in the endolymph of the cochlea, resulting in deafness. In this article we describe the medical history of a toddler diagnosed with JLNS, in whom an arrhythmia was suspected prenatally. At the age of nine months a bilateral sensorineuronal hearing loss was detected. No syncopal events have been reported during betablocker treatment until the age of 2.5 years. Conclusion: A prenatal diagnosis of fetal arrhythmias should raise the suspicion of hereditary primary arrhythmias like LQTS. In case of severe prolongation of QT intervals, particularly when parents are consanguineous, JLNS should be considered and hearing loss should be ruled out. An early diagnosis of JLNS is important to prevent sudden cardiac death and to optimize speech and language development