Muscle ultrasound elastography and MRI in preschool children with Duchenne muscular dystrophy.

The aim of this study was to determine muscle tissue elasticity, measured with shear-wave elastography, in selected lower limb muscles of patients affected by Duchenne muscular dystrophy (DMD) and to correlate the values obtained with those recorded in healthy children and with muscle magnetic resonance imaging (MRI) data from the same DMD children, specifically the pattern on T1-weighted (w) and short-tau inversion recovery (STIR) sequences. Five preschool DMD children and five age-matched healthy children were studied with shear-wave elastography. In the DMD children, muscle stiffness was moderately higher compared with the muscle stiffness in HC, in the rectus femoris, vastus lateralis, adductor magnus and gluteus maximus muscles. On muscle MRI T1-w images showed fatty replacement in 3/5 patients at the level of the GM, while thigh and leg muscles were affected in 2/5; hyperintensity on STIR images was identified in 4/5 patients. No significant correlation was observed between stiffness values and MRI scoring. Our study demonstrated that lower limb muscles of preschool DMD patients show fatty replacement and patchy edema on muscle MRI and increased stiffness on shear-wave elastography. In conclusion, although further studies in larger cohorts are needed, shear-wave elastography could be considered a useful non-invasive tool to easily monitor muscle changes in early stages of the disease.

A novel mutation of the glomulin gene in an Italian family with autosomal dominant cutaneous glomuvenous malformations.

Glomuvenous malformations (GVM) are hamartomas characterized histologically by glomus cells, which should be distinguished from glomus tumors. Familial GVM are rare, often present as multiple lesions, and exhibit familial aggregation, with autosomal dominant transmission. GVM are caused by mutations of the glomulin (GLMN) gene on chromosome 1p21-p22. Their development is thought to follow the 'two-hit' hypothesis, with a somatic mutation required in addition to the inherited germline mutation. We describe a novel GLMN mutation in an Italian family with GVM in which some members present with the less commonly observed phenotype of solitary lesions. A second somatic 'hit' mutation in GLMN was not discovered in our family. We further provide histological, immunohistochemical and electron microscopic data exhibiting the classic features of GVM. The diagnosis of GVM is critical because of distinction from venous malformations and blue rubber bleb nevus syndrome, which may demonstrate clinical similarities but require different treatment.