Ramsay Hunt Syndrome Associated with Varicella-Zoster Virus Encephalitis in a Child.

Ramsay Hunt syndrome (RHS) is a triad of peri-auricular pain, ipsilateral facial nerve palsy and vesicular rash around the ear pinna. It is caused by reactivation of varicella-zoster virus (VZV) that lies dormant in the geniculate ganglia. It can be complicated by VZV encephalitis rarely. We report the case of an 8-year-old previously healthy boy who presented to a tertiary care hospital in Muscat, Oman in 2021 with fever, progressive left ear pain, vesicular rash around his ear pinna and left-sided facial nerve palsy. His course was complicated by VZV encephalitis where he was managed with intravenous (IV) acyclovir and IV corticosteroids. He improved significantly and was asymptomatic with a normal neurology examination at the 6-months follow-up.

Variants in ACTC1 underlie distal arthrogryposis accompanied by congenital heart defects.

Contraction of the human sarcomere is the result of interactions between myosin cross-bridges and actin filaments. Pathogenic variants in genes such as MYH7 , TPM1 , and TNNI3 that encode parts of the cardiac sarcomere cause muscle diseases that affect the heart, such as dilated cardiomyopathy and hypertrophic cardiomyopathy. In contrast, pathogenic variants in homologous genes MYH2 , TPM2 , and TNNI2 , that encode parts of the skeletal muscle sarcomere, cause muscle diseases affecting skeletal muscle, such as the distal arthrogryposis (DA) syndromes and skeletal myopathies. To date, there have been few reports of genes (e.g., MYH7 ) encoding sarcomeric proteins in which the same pathogenic variant affects both skeletal and cardiac muscle. Moreover, none of the known genes underlying DA have been found to contain mutations that also cause cardiac abnormalities. We report five families with DA due to heterozygous missense variants in the gene actin, alpha, cardiac muscle 1 ( ACTC1 ). ACTC1 encodes a highly conserved actin that binds to myosin in both cardiac and skeletal muscle. Mutations in ACTC1 have previously been found to underlie atrial septal defect, dilated cardiomyopathy, hypertrophic cardiomyopathy, and left ventricular noncompaction. Our discovery delineates a new DA condition due to mutations in ACTC1 and suggests that some functions of actin, alpha, cardiac muscle 1 are shared in cardiac and skeletal muscle.