Neurofibromatosis type 1 (NF1) is one of the most frequent genetic disorders, affecting 1:3,000 worldwide. Identification of genotype–phenotype correlations is challenging because of the wide range clinical variability, the progressive nature of the disorder, and extreme diversity of the mutational spectrum. We report 136 individuals with a distinct phenotype carrying one of five different NF1 missense mutations affecting p.Arg1809. Patients presented with multiple café‐au‐lait macules (CALM) with or without freckling and Lisch nodules, but no externally visible plexiform neurofibromas or clear cutaneous neurofibromas were found. About 25% of the individuals had Noonan‐like features. Pulmonic stenosis and short stature were significantly more prevalent compared with classic cohorts (P < 0.0001). Developmental delays and/or learning disabilities were reported in over 50% of patients. Melanocytes cultured from a CALM in a segmental NF1‐patient showed two different somatic NF1 mutations, p.Arg1809Cys and a multi‐exon deletion, providing genetic evidence that p.Arg1809Cys is a loss‐of‐function mutation in the melanocytes and causes a pigmentary phenotype. Constitutional missense mutations at p.Arg1809 affect 1.23% of unrelated NF1 probands in the UAB cohort, therefore this specific NF1 genotype–phenotype correlation will affect counseling and management of a significant number of patients.

BackgroundFloating-Harbor syndrome (FHS) is a rare condition characterized by short stature, delays in expressive language, and a distinctive facial appearance. Recently, heterozygous truncating mutations in SRCAP were determined to be disease-causing. With the availability of a DNA based confirmatory test, we set forth to define the clinical features of this syndrome.Methods and resultsClinical information on fifty-two individuals with SRCAP mutations was collected using standardized questionnaires. Twenty-four males and twenty-eight females were studied with ages ranging from 2 to 52 years. The facial phenotype and expressive language impairments were defining features within the group. Height measurements were typically between minus two and minus four standard deviations, with occipitofrontal circumferences usually within the average range. Thirty-three of the subjects (63%) had at least one major anomaly requiring medical intervention. We did not observe any specific phenotype-genotype correlations.ConclusionsThis large cohort of individuals with molecularly confirmed FHS has allowed us to better delineate the clinical features of this rare but classic genetic syndrome, thereby facilitating the development of management protocols.

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Eliglustat, an oral substrate reduction therapy, is a first-line therapy for adults with Gaucher disease type 1 and a compatible CYP2D6 metabolizer phenotype. Clinicians have requested more information about frequency, timing, and duration of adverse events associated with eliglustat. Adverse event data as of January 31, 2013 for all patients who received at least one dose of eliglustat were pooled from four eliglustat clinical trials (393 patients representing 535 patient-years of exposure). The following 10 adverse events noted in the eliglustat US Prescribing Information (USPI) and EU Summary of Product Characteristics (SmPC) were evaluated with regard to frequency, drug-relatedness, severity, seriousness, duration, and timing of onset: headache, arthralgia, diarrhea, nausea, fatigue, flatulence, abdominal pain, upper abdominal pain, back pain, and extremity pain. Of 393 patients, 334 experienced one or more adverse events. Most patients (92%) continued taking eliglustat; 3% withdrew from a trial due to an adverse event. Among the 10 adverse events evaluated, none was reported as serious and none resulted in discontinuing treatment; most were mild or moderate, reported only once, and not considered eliglustat-related. The majority of adverse events noted in the eliglustat USPI and SmPC were non-serious, occasional, non-severe, and did not lead to drug discontinuation.

The phenotype of mucolipidosis type II (ML II), a disorder of lysosomal enzyme transport, includes mucopolysaccharidosis type I (Hurler syndrome)-like features and dysostosis multiplex, usually apparent after 6 months of age. We describe here the natural history of neonatal hyperparathyroidism, a recently described presentation of ML II. A female neonate presented with multiple fractures and radiological features of osteopenia and 'rickets-like' changes. Longitudinal evaluation, while the patient was treated with vitamin D 800-3,000 IU/day orally, indicated secondary hyperparathyroidism which resolved, biochemically and radiologically, by age 4 months. Neonatal hyperparathyroidism in ML II is severe, transient, and probably secondary to impaired placental calcium transport, simulating a condition observed in the offspring of chronically hypocalcemic mothers.