Clinical and imaging findings in six cases of congenital muscular dystrophy with rigid spine syndrome linked to chromosome 1p (RSMD1)

We report clinical and imaging findings in six cases from five families affected by the form of congenital muscular dystrophy with rigid spine linked to the locus rigid spine muscular dystrophy 1 on chromosome 1p35-36. All cases showed rigidity of the spine, predominant neck and trunk weakness and frequent and severe thoracic scoliosis. Respiratory impairment was always observed in the first decade. Muscle imaging showed a marked involvement of adductors, sartorius and biceps femoris while rectus femoris and gracilis were relatively spared. This pattern of selective muscle involvement was consistent in all six cases and could be easily observed on either computerised tomography or magnetic resonance imaging. The results of this study suggest that muscle imaging, in combination with clinical assessment can help to identify the rigid spine muscular dystrophy 1 form of congenital muscular dystrophy and can help to target the appropriate genetic investigations.     

Lumbar synovial cysts: experience with nine cases

Nine patients treated surgically for lumbar spinal synovial cyst were reviewed. Four patients had synovial, two had ganglion, one had posterior longitudinal ligament, and two had ligamentum flavum cyst. Synovial cysts had a single layer of epithelial cells in the inner layer of the cyst with continuity with the facet joint. Ganglion cyst had no continuity with the facet joint and epithelial lining was present in one and absent in one case. Posterior longitudinal ligament and ligamentum flavum cysts had no continuity with the facet joint and no epithelial lining. Magnetic resonance imaging showed the cysts better than computed tomography. All patients treated for nerve root compression or lumbar spinal canal narrowing. One patient suffered recurrence 1 year later and was reoperated. Operative results were excellent in six and good in three patients. Lumbar spinal synovial cysts should be considered in differential diagnosis of lumbar radiculopathy/neurogenic claudication and is surgically treatable.     

DNAJC21-related thrombocytopenia in a young adult female

Bone marrow failure type 3 (BMFS3) (MIM:617052) is a subtype of inherited bone marrow failure syndromes (IBMFS) caused by homozygous pathogenic variants in DNAJC21. It was first defined in 2016, and to date, 19 patients have been reported. Here we report the first adult patient; a 20-year-old female with a novel frameshift variant in DNAJC21 presents with thrombocytopenia, dysmorphic findings, and ovarian agenesis. Our patient expands the clinical spectrum to the milder end and suggests that DNAJC21-related disorders can have relatively mild presentations. Investigation of DNAJC21 variants in both childhood and adult patients with persistent, non-progressive thrombocytopenia will allow to broaden the gene-related phenotypic and genotypic spectrum and elucidate the pathophysiology. Therefore, we encourage revisiting undiagnosed patients to offer whole exome sequencing (WES) in adulthood.