IGSF1 deficiency is a rare X-linked condition characterized by central hypothyroidism and a wide variety of other clinical features with variable prevalence, including a delayed pubertal... Show moreIGSF1 deficiency is a rare X-linked condition characterized by central hypothyroidism and a wide variety of other clinical features with variable prevalence, including a delayed pubertal testosterone rise and growth spurt in the context of normal or accelerated testicular growth, and adult macroorchidism with relatively low serum testosterone concentrations. Other features include increased waist circumference, attention deficit, prolactin deficiency and transient partial growth hormone (GH) deficiency in childhood, contrasting with an increased GH secretion in adulthood. Patients with this disorder are not detected shortly after birth if neonatal screening programs are based on thyroid-stimulating hormone (TSH) concentrations. A 13.2-year-old male patient was referred to pediatric endocrinology for evaluation of short stature. He was born large for gestational age into a nonconsanguineous family. During work-up for short stature, deficiencies of TSH, prolactin and GH were detected, leading to treatment with levothyroxine and GH. At 16.9 years, GH treatment was stopped and during transition to adult care, his insulin-like growth factor 1 level was above the normal range. This prompted an analysis of IGSF1, in which a novel hemizygous variant causing a stop codon at c.3559C>T (p.Q1187*) was found, confirming the diagnosis of IGSF1 deficiency syndrome. In this report, we describe his clinical and hormonal characteristics at presentation and during long-term follow-up. Show less
Ghanny, S.; Zidell, A.; Pedro, H.; Joustra, S.D.; Losekoot, M.; Wit, J.M.; Aisenberg, J. 2021
Our objective was to further expand the spectrum of clinical characteristics of the IGSF1 deficiency syndrome in affected males. These characteristic include almost universal congenital central... Show moreOur objective was to further expand the spectrum of clinical characteristics of the IGSF1 deficiency syndrome in affected males. These characteristic include almost universal congenital central hypothyroidism (CeH) with disharmonious pubertal development (normally timed testicular growth, but delayed rise of serum testosterone), macroorchidism, increased body mass index (BMI), and decreased attentional control. In addition, a subset of patients show prolactin deficiency, transient partial growth hormone deficiency in childhood and increased growth hormone secretion in adulthood. We present a family in which the proband was diagnosed with CeH and low serum prolactin. Severe weight gain started at two years old, with a BMI of 42.3 at 13.9 years. Testicular enlargement (5-6 mL, 3.8-4.3 standard deviation score) started aged three years. A pathogenic variant was found in the IGSF1 gene: c.3411_3412del, p.(Tyr1137*). His brother was referred for short stature at age 13 years and was diagnosed with CeH, normal serum prolactin and IGF-1, and disharmonious puberty. In four male relatives (the proband's brother and three cousins) with the variant (one adult), free thyroxine (fT4) was below the lower limit of the reference range in two, and just above this limit in the other two. Three were overweight or obese, adolescents had disharmonious pubertal development and the adult had profound macroorchidism. In conclusion, male hemizygous carriers of a pathogenic IGSF1 variant can present with fT4 concentration above the lower limit of the reference range while severe early onset obesity or premature testicular growth are part of the phenotypic spectrum. Show less
Assessment and management of children with growth failure has improved greatly over recent years. However, there remains a strong potential for further improvements by using novel digital... Show moreAssessment and management of children with growth failure has improved greatly over recent years. However, there remains a strong potential for further improvements by using novel digital techniques. A panel of experts discussed developments in digitalization of a number of important tools used by pediatric endocrinologists at the third 360 degrees European Meeting on Growth and Endocrine Disorders, funded by Merck KGaA, Germany, and this review is based on those discussions. It was reported that electronic monitoring and new algorithms have been devised that are providing more sensitive referral for short stature. In addition, computer programs have improved ways in which diagnoses are coded for use by various groups including healthcare providers and government health systems. Innovative cranial imaging techniques have been devised that are considered safer than using gadolinium contrast agents and are also more sensitive and accurate. Deep-learning neural networks are changing the way that bone age and bone health are assessed, which are more objective than standard methodologies. Models for prediction of growth response to growth hormone (GH) treatment are being improved by applying novel artificial intelligence methods that can identify non-linear and linear factors that relate to response, providing more accurate predictions. Determination and interpretation of insulin-like growth factor-1 (IGF-1) levels are becoming more standardized and consistent, for evaluation across different patient groups, and computer-learning models indicate that baseline IGF-1 standard deviation score is among the most important indicators of GH therapy response. While physicians involved in child growth and treatment of disorders resulting in growth failure need to be aware of, and keep abreast of, these latest developments, treatment decisions and management should continue to be based on clinical decisions. New digital technologies and advancements in the field should be aimed at improving clinical decisions, making greater standardization of assessment and facilitating patient-centered approaches. Show less
Wit, J.M.; Sas, T.C.J.; Ranke, M.B.; Dommelen, P. van 2021
Objective: We hypothesized that modelling catch-up growth (CUG) as developed for coeliac disease (CD), might also fit CUG in adequately treated children with juvenile hypothyroidism (JHT) or growth... Show moreObjective: We hypothesized that modelling catch-up growth (CUG) as developed for coeliac disease (CD), might also fit CUG in adequately treated children with juvenile hypothyroidism (JHT) or growth hormone deficiency (GHD).Methods: We used a monomolecular function for all available prepubertal data on height standard deviation score (HSDS) minus target height SDS (adjHSDS) in children with JHT (n=20) and GHD (n=18) on a conventional (CoD) or high GH dose (HD), based either on a national height reference with an age cut-off of 10 (girls) and 12 (boys) years (model 1) or prepubertal height reference values, if age (0) was >= 3, with no upper age limit (model 2).Results: The models could be fitted in 83-90% of cases; in other cases the HSDS decreased after several measurements, which violated the assumption of an irreversible growth process. In JHT, the rate constant (k) and adjHSDS (0) were lower than in CD (p=0.02), but adjHSDS (end) was similar. In GHD (model 1), k was lower than for CD (p=0.004) but similar to JHT, while adjHSDS (0) and adjHSDS (end) were similar to CD and JHT. Thus, the shape of CUG is similar for children with JHT and GHD, while children with CD had less growth deficit at start and a faster CUG. The differences in CUG parameters between GH dose subgroups did not reach statistical significance.Conclusion: Modelling CUG of prepubertal children with JHT and GHD can be used for assessing the adequacy of CUG and the influence of clinical treatment modalities on its speed and magnitude. Show less
Wit, J.M.; Bidlingmaier, M.; Bruin, C. de; Oostdijk, W. 2020
The serum insulin-like growth factor-I (IGF-I) concentration is commonly used as a screening tool for growth hormone deficiency (GHD), but there is no consensus on the cut-off limit of IGF-I... Show moreThe serum insulin-like growth factor-I (IGF-I) concentration is commonly used as a screening tool for growth hormone deficiency (GHD), but there is no consensus on the cut-off limit of IGF-I standard deviation score (SDS) to perform GH stimulation tests for confirmation or exclusion of GHD. We argue that the cut-off limit is dependent on the clinical pre-test likelihood of GHD and propose a diagnostic strategy in which the cut-off limit varies between zero to -2 SDS. Show less
