Heike Kölbel

Hyperleptinemia in children with autosomal recessive spinal muscular atrophy type I-III

Background Autosomal-recessive proximal spinal muscular atrophies (SMA) are disorders characterized by a ubiquitous deficiency of the survival of motor neuron protein that leads to a multisystemic disorder, which mostly affects alpha motor neurons. Disease progression is clinically associated with failure to thrive or weight loss, mainly caused by chewing and swallowing difficulties. Although pancreatic involvement has been described in animal models, systematic endocrinological evaluation of the energy metabolism in humans is lacking. Methods In 43 patients with SMA type I-III (8 type I; 22 type II; 13 type III), aged 0.6–21.8 years, auxological parameters, pubertal stage, motor function (Motor Function Measurement 32 –MFM32) as well as levels of leptin, insulin glucose, hemoglobin A1c, Homeostasis Model Assessment index and an urinary steroid profile were determined. Results Hyperleptinemia was found in 15/35 (43%) of our patients; 9/15 (60%) of the hyperleptinemic patients were underweight, whereas 1/15 (7%) was obese. Hyperleptinemia was associated with SMA type (p = 0.018). There was a significant association with decreased motor function (MFM32 total score in hyperleptinemia 28.5%, in normoleptinemia 54.7% p = 0.008, OR 0.969; 95%-CI: 0.946–0.992). In addition, a higher occurrence of hirsutism, premature pubarche and a higher variability of the urinary steroid pattern were found. Conclusion Hyperleptinemia is highly prevalent in underweight children with SMA and is associated with disease severity and decreased motor function. Neuronal degradation of hypothalamic cells or an increase in fat content by muscle remodeling could be the cause of hyperleptinemia.

Outcome after Robotic-Assisted Thymectomy in Children and Adolescents with Acetylcholine Receptor Antibody-Positive Juvenile Myasthenia Gravis

Abstract The aim of our study was to describe the long‐term outcomes after robotic‐assisted thymectomy in a cohort of acetylcholine receptor (AChR)‐antibody (Ab)‐positive, generalized juvenile myasthenia gravis (JMG). We retrospectively analyzed a cohort of 18 patients (15 females and 3 males) who underwent robotic‐assisted thymectomy. At the time of diagnosis, 12/18 patients were prepubertal; the mean age was 9.8 years at the onset of the disease. All patients received therapy with pyridostigmine; additional immunotherapy included: corticosteroid therapy in 18/18, azathioprine in 14/18 patients, mycophenolate mofetil in 4/18, and cyclosporine in 1/18 patients. Eight patients received intravenous immunoglobulin and four plasma exchange. The mean age of patients at thymectomy was 11.7 years (range: 4.2‐16 years). The mean duration of postoperative stay was 2.9 days. Thymectomy was followed by gradual clinical improvement (39% patients achieved clinical remission) and dose reduction in steroid therapy in all patients during the follow‐up period (mean: 27.4 months). In children and adolescents with AChR‐Ab‐positive JMG, thymectomy has a beneficial effect on the weaning off immunosuppressive therapy in patients with generalized symptoms and should be considered as a part of multimodal therapy. Robotic‐assisted thymectomy is a safe procedure with low morbidity and a comparable clinical outcome compared with the open sternal procedure.

Correction: Hyperleptinemia in children with autosomal recessive spinal muscular atrophy type I-III

[This corrects the article DOI: 10.1371/journal.pone.0173144.].

Deep intronic variants introduce DMD pseudoexon in patient with muscular dystrophy

Dystrophinopathies are X-linked muscle diseases caused by mutations in the large DMD gene. The most common mutations are detected by standard diagnostic techniques. However, some patients remain without detectable mutation, most likely due to changes in the non-coding sequence. We report on a boy with complete absence of dystrophin in muscle biopsy but no causative mutation according to standard diagnostics. To search for deep intronic variations (DIV) in the DMD gene we isolated mRNA from muscle tissue and amplified overlapping cDNA fragments using RT-PCR. One cDNA product revealed an augmented fragment size showing an insertion of 77 bp between the exons 7 and 8 by sequencing. We sequenced the flanking sequences of gDNA and found two hemizygous single nucleotide variants (c.650-39575 A>C and c.650-39498 A>G) surrounding the inserted fragment. Both variants create cryptic splice sites which initiate the formation of a pseudoexon that produces a frameshift in the DMD gene.