hrp0082p1-d2-216 | Reproduction (1) | ESPE2014

IGSF1 Variants in Boys with Familial Delayed Puberty

Joustra Sjoerd , Wehkalampi Karoliina , Oostdijk Wilma , Biermasz Nienke , Howards Sasha , Bernard Daniel , Maarten Wit Jan , Dunkel Leo , Losekoot Monique

Background: The immunoglobulin superfamily member 1 (IGSF1) gene encodes a plasma membrane glycoprotein enriched in pituitary and testes. Loss-of-function mutations in IGSF1 cause an X-linked syndrome of central hypothyroidism (CeH), macroorchidism, and delayed pubertal rise of testosterone despite normal timing of testicular growth. This syndrome was discovered in patients with CeH; therefore, it is presently unknown whether IGSF1 mutations also cau...

hrp0086p1-p462 | Fat Metabolism and Obesity P1 | ESPE2016

Determinants of Advanced Bone Age in Childhood Obesity

Jan de Groot Cornelis , van den Berg Adriaan , Ballieux Bart , Kroon Herman , Rings Edmond , Maarten Wit Jan , van den Akker Erica

Background: Childhood obesity is associated with advanced bone age (BA), leading to an altered growth pattern. Previous results of studies suggest that androgens, estrogens, sex hormone binding globulin (SHBG) and insulin are responsible for this phenomenon, but results are contradictory and might be biased by confounders.Objective and hypotheses: To investigate the independent effects of estrogens, androgens, SHBG and insulin parameters on BA advancemen...

hrp0082p1-d2-217 | Reproduction (1) | ESPE2014

Reference Charts for Testicular Volume in Dutch Children and Adolescents

Joustra Sjoerd , van der Plas Evelyn , Goede Joery , Oostdijk Wilma , Delemarre - Van de Waal Henriette , Hack Wilfried , van Buuren Stef , Maarten Wit Jan

Background: Measurement of testicular volume is important when conditions associated with a delay or advance in the onset of puberty, or micro- and macroorchidism, are suspected. Measured testicular volumes must be compared with reference data, preferably expressed in S.D. curves using the LMS method, as is routinely done for many auxological measurements in pediatrics. The current study therefore aimed to construct LMS-smoothed age-reference charts for testicul...

hrp0097p1-119 | Growth and Syndromes | ESPE2023

Clinical features and response to rhGH treatment in ten patients with heterozygous IGF1 variants

Punt Lauren , van der Kaay Danielle , van Setten Petra , Bocco Gianni , de Munnik Sonja , Losekoot Monique , van Duyvenvoorde Hermine , de Bruin Christiaan , Maarten Wit Jan , Joustra Sjoerd

Introduction: Patients carrying homozygous IGF1 loss-of-function mutations are extremely rare and show severe pre- and postnatal growth failure, microcephaly, developmental delay, retrognathia and sensorineural deafness. Heterozygous variants in IGF1 appear to be more common in short stature, but only few cases have been reported in detail. Therefore, clinical features and growth response to recombinant human growth hormone (rhGH) therapy are...

hrp0097fc4.3 | Growth and syndromes (to include Turner syndrome) | ESPE2023

Pathogenic variants in GHSR cause short stature and growth hormone neurosecretory dysfunction; results from a large case series

Punt Lauren , Kooijman Sander , van der Kaay Danielle , van Tellingen Vera , Bakker - van Waarde Willie , Boot Annemieke , van den Akker Erica , van Boekholt Anneke , van Duyvenvoorde Hermine , van Nieuwaal - Van Maren Nancy , Woltering Claire , Heijligers Malou , van der Heyden Josine , Bannink Ellen , Losekoot Monique , de Bruin Christiaan , Maarten Wit Jan , Joustra Sjoerd

Introduction: Ghrelin binds to its receptor GHSR1A, encoded by GHSR, on somatotrophs of the pituitary. Growth hormone (GH) secretion is enhanced by ghrelin binding as well as the receptor’s constitutive activity. Results from in vitro experiments, knock-out mice, and GWAS suggest that heterozygous loss-of-function of GHSR may be associated with short stature, but observations in case studies are equivocal. We aimed to better ch...

hrp0097p1-318 | Growth and Syndromes | ESPE2023

15-year experience with the IGF1 generation test in the Netherlands

Kruijsen Anne , de Groote Kirsten , Punt Lauren , van Trotsenburg Paul , Pijnenburg-Kleizen Karijn , Bocco Gianni , Berkenbosch Lizanne , van Setten Petra , Claahsen - van der Grinten Hedi , van der Kaay Danielle , Schott Nina , van Tellingen Vera , van Mill Edgar , van der Heyden Josine , Brandsma Annelies , Hendriks Yvonne , Losekoot Monique , van Duyvenvoorde Hermine , Hokken-Koelega Anita , Renes Judith , Maarten Wit Jan , de Bruin Christiaan , Joustra Sjoerd

Introduction: Among children with short stature, some show persistent IGF-I levels <-2.0 SDS despite a normal growth hormone (GH) response in a stimulation test. This may be caused by conditions that could benefit from recombinant human GH (rhGH) therapy (e.g. GH neurosecretory dysfunction, bioinactive GH, partial GH insensitivity). Therefore, the IGF-I generation test (IGFIGT) was implemented in 2006 using a national, standardized protocol. Children with a...