Different Molecular Signatures in Magnetic Resonance Imaging-Staged Facioscapulohumeral Muscular Dystrophy Muscles

Facioscapulohumeral muscular dystrophy (FSHD) is one of the most common muscular dystrophies and is characterized by a non-conventional genetic mechanism activated by pathogenic D4Z4 repeat contractions. By muscle Magnetic Resonance Imaging (MRI) we observed that T2-short tau inversion recovery (T2-STIR) sequences identify two different conditions in which each muscle can be found before the irreversible dystrophic alteration, marked as T1-weighted sequence hyperintensity, takes place. We studied these conditions in order to obtain further information on the molecular mechanisms involved in the selective wasting of single muscles or muscle groups in this disease

Andersen syndrome: an association of periodic paralysis, cardiac arrhythmia and dysmorphic abnormalities Síndrome de Andersen: uma associação de paralisia periódica com arritmia cardíaca e alterações dismórficas

Andersen syndrome (AS) is a rare disease characterized by the presence of periodic paralysis (PP), cardiac arrhythmia and dysmorphic abnormalities. We report 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-year-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.<br>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 apresentando SA, e que também apresenta obesidade e apnéia obstrutiva do sono (AOS). Avaliações clínica e genética 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