Mutant Tbl1x male mice have a short life span and do not breed: unexpected findings.

Humans with the mutation Y509C in transducin beta like 1 X-linked (TBL1X HGNC ID HGNC:11585) have been reported to present with the combination of central congenital hypothyroidism and impaired hearing. TBL1X belongs to the WD40 repeat-containing protein family, is part of NCoR and SMRT corepressor complexes, and thereby involved in thyroid hormone signaling. In order to investigate the effects of the Y509C mutation in TBL1X on cellular thyroid hormone action, we aimed to generate a hemizygous male mouse cohort carrying the Tbl1x Y459C mutation which is equivalent to the human TBL1X Y509C mutation using CRISPR/Cas9 technology. Hemizygous male mice were small at birth and inactive. Their life span (median life span 93 days) was very short compared with heterozygous female mice (survived to >200 days with no welfare issues). About 52% of mice did not survive to weaning (133 mice). Of the remaining 118 mice, only 8 were hemizygous males who were unable to mate whereby it was impossible to generate homozygous female mice. In conclusion, the Tbl1x Y459C mutation in male mice has a marked negative effect on birth weight, survival, and fertility of male mice. The present findings are unexpected as they are in contrast to the mild phenotype in human males carrying the equivalent TBL1X Y509C mutation.

Pediatric Graves' orbitopathy: a multicentre study.

PURPOSE: Graves' orbitopathy (GO) is a rare condition in children often considered to be a less severe condition than at an older age. The aim of our study was to analyse if there are any factors that distinguish paediatric from adult GO in order to provide guidelines for assessing and managing paediatric GO. METHODS: Study design is a multicentre retrospective observational case series; 115 paediatric patients diagnosed with GO who visited our university medical centres in the Netherlands and Iran between 2003 and 2019 were submitted for complete ophthalmological examinations, serological testing and/or orbital imaging. Main outcome measures focussed on the natural course and clinical picture as well as medical and surgical treatment in paediatric GO. RESULTS: Clinical findings included proptosis (n = 97; 84.3%), eyelid retraction (n = 77; 67%) and diplopia (n = 13; 11.3%). Ninety-two patients (80%) presented with mild disease, 21 (18.3%) with moderate-severe disease and two (1.7%) with severe GO. Five patients (4.3%) underwent intravenous glucocorticoids and 25 patients underwent orbital decompression surgery. Strabismus surgery due to primary involvement of extraocular muscles was performed in two patients (1.7%). Overall, rehabilitative surgical treatment was planned in 31 patients (26.9%) with inactive disease. Two patients experienced reactivation of the disease. CONCLUSION: Despite the fact that paediatric and adult GO are considered two separate entities, they might be the same disease with two different clinical phenotypes. Paediatric GO population presents with a comparable clinical picture regarding both soft tissue involvement and proptosis, which may require surgical intervention. Proptosis was present in the majority of paediatric GO patients. Orbital decompression was performed in 21.7% of patients.

High Prevalence of Weight Gain in Childhood Brain Tumor Survivors and Its Association With Hypothalamic-Pituitary Dysfunction.

PURPOSE: Childhood brain tumor survivors (CBTS) are at risk for developing obesity, which negatively influences cardiometabolic health. The prevalence of obesity in CBTS may have been overestimated in previous cohorts because of inclusion of children with craniopharyngioma. On the contrary, the degree of weight gain may have been underestimated because of exclusion of CBTS who experienced weight gain, but were neither overweight nor obese. Weight gain may be an indicator of underlying hypothalamic-pituitary (HP) dysfunction. We aimed to study prevalence of and risk factors for significant weight gain, overweight, or obesity, and its association with HP dysfunction in a national cohort of noncraniopharyngioma and nonpituitary CBTS. METHODS: Prevalence of and risk factors for significant weight gain (body mass index [BMI] change ≥ +2.0 standard deviation score [SDS]), overweight, or obesity at follow-up, and its association with HP dysfunction were studied in a nationwide cohort of CBTS, diagnosed in a 10-year period (2002-2012), excluding all craniopharyngioma and pituitary tumors. RESULTS: Of 661 CBTS, with a median age at follow-up of 7.3 years, 33.1% had significant weight gain, overweight, or obesity. Of the CBTS between 4 and 20 years of age, 28.7% were overweight or obese, compared with 13.2% of the general population between 4 and 20 years of age. BMI SDS at diagnosis, diagnosis of low-grade glioma, diabetes insipidus, and central precocious puberty were associated with weight gain, overweight, or obesity. The prevalence of HP dysfunction was higher in overweight and obese CTBS compared with normal-weight CBTS. CONCLUSION: Overweight, obesity, and significant weight gain are prevalent in CBTS. An increase in BMI during follow-up may be a reflection of HP dysfunction, necessitating more intense endocrine surveillance.

Hypothalamic obesity after treatment for craniopharyngioma: the importance of the home environment.

Hypothalamic obesity after treatment for craniopharyngioma is a well-recognized, severe problem. Treatment of hypothalamic obesity is difficult and often frustrating for the patient, the parents and the professional care-giver. Because hypothalamic obesity is caused by an underlying medical disorder, it is often assumed that regular diet and exercise are not beneficial to reduce the extraordinarily high body mass index, and in fact, lifestyle interventions have been shown to be insufficient in case of extreme hypothalamic obesity. Nevertheless, it is important to realize that also in this situation, informal care delivered by the family and appropriate parenting styles are required to minimize the obesity problem. We present a case in which weight gain in the home situation was considered unstoppable, and a very early mortality due to complications of the severe increasing obesity was considered inevitable. A permissive approach toward food intake became leading with rapid weight increase since a restrictive lifestyle was considered a senseless burden for the child. By admission to our hospital for a longer period of time, weight reduction was realized, and the merely permissive approach could be changed into active purposeful care by adequate information, instruction, guidance and encouragement of the affected child and her parents. This case illustrates that, although this type of obesity has a pathological origin, parental and environmental influences remain of extreme importance.

[Substitution of dexamethasone for dexamphetamine due to their written and spoken similarity]. / Verwisseling dexamfetamine en dexamethason door lees- en klankgelijkenis.

We present a 15-year-old girl and an 11-year-old boy who were prescribed dexamphetamine for treatment of Attention Deficit Hyperactivity Disorder (ADHD), and who subsequently presented with symptoms indicative of Cushing's syndrome. It turned out that both children had taken high doses of dexamethasone instead of dexamphetamine due to an error made by the pharmacist. The diagnosis of exogenous Cushing's syndrome is easily made. However, it is a serious condition with possibly severe and persistent complications. The substitution of dexamethasone for dexamphetamine has been described before. Both doctors and pharmacists should be aware of this possible error.