Congenital long QT syndrome may present as nocturnal enuresis- Case report

The researchers reported about a young and ostensibly healthy female, who was referred for evaluation following two episodes of unexplained bedwetting that occurred 2 years apart, at 18 and 20 years of age. On both occasions she reported awakening feeling well, only to notice she had passed urine in bed during sleep. She was presented with no other symptoms, with no history of consuming alcohol or illegal substances.

Her urine tests and abdominal ultrasound were normal. On both occasions, she was treated with empiric antibiotic therapy for a presumed (yet unconfirmed) urinary tract infection. Unfortunately, she passed away in her sleep at the age of 23 years, 3 years after her most recent event of unexplained bedwetting.

The researchers further evaluated the cardiac function of her mother as cascade screening of familial sudden death. In response to direct questioning, the mother mentioned that 2 additional family members had died suddenly at a young age.

Although the mother's cardiac evaluation was normal, the researchers observed a prolonged QT interval with T-wave morphology suggestive of congenital long QT syndrome type II in the echocardiogram. The genetic evaluation with an expanded gene panel of arrhythmia and cardiomyopathy genes (including 168 genes) further confirmed the diagnosis of congenital long QT syndrome type II by identifying a pathogenic mutation in KCNH2, the gene that, based on the phenotype, was expected to be disease-causing [KCNH2: c.2699_2760dup (p.Gly921Serfs∗74)].

The researchers further conducted an online survey of physicians about their selection of diagnostic methods apropos of this particular case. They noted that only 1% of the physicians who responded to the survey thought that an electrocardiogram should be part of the diagnostic workup of a young adult patient with unexplained bedwetting and 19% said they would do an EEG for nocturnal epileptic seizures.

The authors wrote, "We are not suggesting that every child with bedwetting should undergo electrocardiographic recording, as this would likely lead to significant overdiagnosis. However, inquiring about a familial history of sudden death should be part of every medical consultation. Performing an electrocardiogram is considered an essential (quasi-mandatory) step in the evaluation of syncope because patients who present with cardiogenic syncope but remain unrecognized and untreated have a very high mortality risk."

They concluded, "It is time to raise awareness among primary physicians that potentially lethal arrhythmic conditions can present with sporadic nocturnal enuresis. These conditions are detectable via family and clinical history in combination with an electrocardiogram."

For further information:

DOI: https://doi.org/10.1016/j.hrthm.2022.01.031