Hereditary neuropathy with liability to pressure palsies (HNPP): Intrafamilial phenotypic variability and early childhood refusal to walk as the presenting symptom.

BACKGROUND: Limping and/or refusal to walk is a common complaint in the setting of the pediatric department, with a widely diverse differential diagnosis. An unusual etiology, is that of a hereditary neuropathy. Hereditary neuropathy with liability to pressure palsies (HNPP) is a recurrent, episodic demyelinating neuropathy, most commonly caused by a 17p11.2 chromosomal deletion encompassing the PMP22 gene. METHODS: We pursued chromosomal microarray analysis (CMA) in multiple affected individuals of a single extended family, manifesting a range of phenotypic features consistent with HNPP. RESULTS: A 4.5 years-old boy presented for in-patient evaluation due to refusal to walk. Initial investigations including spine MRI and bone scan failed to yield a conclusive diagnosis. Following family history, which implied an autosomal dominant mode of inheritance, CMA was pursued and confirmed a 17p11.2 deletion in the proband consistent with HNPP. Importantly, following this diagnosis, four additional affected family members were demonstrated to harbor the deletion. Their variable phenotypic features, ranging from a prenatal diagnosis of a 6 months-old sibling, to recurrent paresthesias manifesting in the fourth decade of life, are discussed. CONCLUSIONS: Our experience with the family reported herein demonstrates how a thorough anamnesis can lead to a rare genetic etiology with a favorable prognosis and prevent unnecessary investigations, and underscores HNPP as an uncommon diagnostic possibility in the limping child.

Primary Ovarian Insufficiency Nationwide Incidence Rate and Etiology Among Israeli Adolescents.

PURPOSE: The aim of the study was to estimate the current incidence and the distribution of etiologies of primary ovarian insufficiency (POI) in a nationwide study. The prevalence of POI in young adult women has recently increased, but the data cited for adolescents are more than three decades old. METHODS: Data regarding females aged <21 years diagnosed with POI during the years 2000-2016 were collected from all the pediatric endocrinology units in Israel. POI was defined by at least 4 months of amenorrhea in association with menopausal levels of follicle-stimulating hormone. Iatrogenic cases were excluded. RESULTS: For the 130 females aged <21 years included in the study, the distribution of POI etiologies was Turner syndrome/mosaicism in 56 (43%), idiopathic in 35 (27%), and other (developmental, genetic, metabolic, adrenal, and autoimmune) in 39 (30%) females. During the years 2009-2016, compared with 2000-2008, the incidence rate of new POI diagnoses per 100,000 person-years doubled (4.5 vs. 2.0; p value <.0001), and incidence rates of idiopathic and other etiologies increased by 2.6 (p value = .008) and 3.0 (p value = .002), respectively. In contrast, the incidence of Turner syndrome was constant (p value = .2). In the age group of 15-21 years, the current incidence of non-Turner POI in adolescents is one per 100,000 person-years. CONCLUSIONS: In this nationwide study, the incidence rate of POI in youth aged <21 years was one tenth of the rate that is commonly cited. A significant increase in the rate of POI in non-Turner females was observed over the last decade. Contributions of environmental and epigenetic factors should be studied.