Andersen syndrome: an association of periodic paralysis, cardiac arrhythmia and dysmorphic abnormalities

Abstract

-Andersen syndrome (AS) is a rare disease characterized by the presence of periodic paralysis (PP), cardiac arrhythmia and dysmorphic abnormalities. We re p o rt herein the first Brazilian patient presenting AS who also had obesity, obstructive sleep apnea (OSA) and daytime sleepiness. Clinical and genetic evaluation of six family members demonstrated that four had dysmorphic abnormalities but none had PP or cardiac arrhythmia. Sequencing of KCNJ2 revealed the R218W mutation in the index patient and her 6 -y e a r-old daughter, who presented dysmorphic abnormalities (micrognathia, clinodactyly of fourth and fifth fingers, short stature) and OSA. Three relatives had clinodactyly as the only manifestation but the R218W mutation was absent, suggesting that this characteristic may be influenced by another gene. OSA accompanied by dysmorphic features may be related to AS.KEY WORDS: periodic paralysis, cardiac arrhythmia, dysmorphism, obstructive sleep apnea.S í n d rome de Andersen: uma associação de paralisia periódica com arritmia cardíaca e alterações dismórficas RESUMO -A síndrome de Andersen (SA) é doença rara caracterizada pela presença de paralisia periódica (PP), arritmia cardíaca e anormalidades dismórficas. Relatamos o primeiro paciente brasileiro apre s e n t a ndo SA, e que também apresenta obesidade e apnéia obstrutiva do sono (AOS). Avaliações clínica e genéti-ca de seis familiares demonstraram que quatro apresentavam alterações dismórficas mas nenhum tinha PP ou arritmia cardíaca. O sequenciamento do gene KCNJ2 revelou a mutação R218W no paciente índex e sua filha de 6 anos, que apresentava alterações dismórficas (micrognatia, clinodactilia do quarto e quinto dedos, baixa estatura) e AOS. Três familiares tinham clinodactilia como única manifestação mas a mutação R218W estava ausente, sugerindo que esta característica seja influenciada por outro gene. A AOS associada a alterações dismórficas pode estar relacionada à SA. PALAVRAS-CHAVE: paralisia periódica, arritmia cardíaca, dismorfismo, apnéia obstrutiva do sono.

Andersen-Tawil Syndrome with High Risk of Sudden Cardiac Death in Four Mexican Patients. Cardiac and Extra-Cardiac Phenotypes

“…The group of patients informed in literature had a range of 5-73 years old. This variant is considered as a hotspot according to literature 1,7,8,12,16,17,[28][29][30][31][32][33] , male cases have less affectation in cardiac and skeletal muscle, and facial and skeletal studies are under-reported, the clinical variable expression is a constant, and sudden death in 11% of the patients informed in the literature 7,16,34 .…”

Andersen-Tawil syndrome (ATS) – Case report and literature review

“…Skeletal anomalies included small hands and feet, brachydactyly, 2-3 toe syndactyly and toe clinodactyly. Tengan et al [15] described a 33-year-old Brazilian male with episodic weakness and facial and skeletal dysmorphic features, such as clinodactyly of the fourth and fifth fingers, short stature, thoracic scoliosis, high arched palate, micrognathia and retrognathia. Detection of a mutation in the KCNJ2 gene confirmed the diagnosis of ATS.…”