0000000001070171
AUTHOR
Marius Bartsch
Skeletal abnormalities of the upper limbs--neonatal diagnosis of 49,XXXXY syndrome.
A case of neonatal diagnosis of 49,XXXXY syndrome is presented. Clinical identification was prompted by a bilateral thickening of the radioulnar joints and X-ray imaging disclosing almost complete radioulnar synostosis. Conventional karyotyping was initiated and revealed a karyotype of 49,XXXXY. Previously reported neonatal symptoms such as low birth weight, muscular hypotonia, or genital malformations were absent in this case. Microsatellite analysis showed two different X chromosomes each present in two copies, supporting that the four X chromosomes had arisen from a nondisjunction in maternal meiosis I followed by a second nondisjunction involving both X chromosomes in meiosis II. Multid…
Neonatal Respiratory Insufficiency Caused by an (Homozygous) ABCA3-Stop Mutation: a Systematic Evaluation of Therapeutic Options
Background Autosomal recessive ABCA3 (ATP-binding cassette protein A3) gene mutations have been associated with neonatal respiratory distress and pediatric interstitial lung disease. The clinical course of the disease depends on the underlying mutations. Therefore, knowledge of course, symptoms and treatment of the disease is important. Patient and methods A term newborn suffered from progressive respiratory insufficiency, which led to death at the age of 4.8 months. The girl developed interstitial lung disease. Infections as well as structural and functional disorders of the lung were systematically excluded. A homozygous c.4681C > T (Arg 1561 Stop) mutation of the ABCA3 gene was identifie…
New Hyperekplexia Mutations Provide Insight into Glycine Receptor Assembly, Trafficking, and Activation Mechanisms*
Hyperekplexia is a syndrome of readily provoked startle responses, alongside episodic and generalized hypertonia, that presents within the first month of life. Inhibitory glycine receptors are pentameric ligand-gated ion channels with a definitive and clinically well stratified linkage to hyperekplexia. Most hyperekplexia cases are caused by mutations in the α1 subunit of the human glycine receptor (hGlyR) gene (GLRA1). Here we analyzed 68 new unrelated hyperekplexia probands for GLRA1 mutations and identified 19 mutations, of which 9 were novel. Electrophysiological analysis demonstrated that the dominant mutations p.Q226E, p.V280M, and p.R414H induced spontaneous channel activity, indicat…