A 14-year-old girl with premature ovarian insufficiency but with a positive pregnancy test.

OBJECTIVES: Childhood cancer survivors are at risk for premature ovarian insufficiency, especially after treatment with alkylating agents. The objective of this report is to highlight a case in which this phenomenon caused a false-positive pregnancy test. CASE PRESENTATION: A workup was performed in a 14-year-old girl with a positive pregnancy test. She was diagnosed with stage IV neuroblastoma of the left adrenal gland at the age of 4 years. She received extensive treatment, including alkylating agents, and had been diagnosed with premature ovarian insufficiency. An LH/hCG suppression test was performed using high dose 17 bèta-estradiol: hCG levels normalized. CONCLUSIONS: The pregnancy test was false-positive due to production of low amounts of hCG by the pituitary gland as a result of high LH concentrations following premature ovarian insufficiency. It may be helpful to perform the LH/hCG suppression test to prove pituitary origin of the hCG overproduction.

Elevated IGF-1 concentrations in children with low grade glioma: A descriptive analysis in a retrospective national cohort.

Children with low grade glioma (LGG) may present with, or develop, elevated concentrations of insulin-like growth factor 1 (IGF-1). The prevalence, pathophysiology, or its possible clinical effects are poorly understood. Our aim was to evaluate the prevalence of such elevated IGF-1 concentrations and to describe its association with linear growth, body mass index (BMI), pituitary outcome, and tumor behavior in a large retrospective national cohort. From a nationwide retrospective cohort of pediatric brain tumor survivors diagnosed between 2002 and 2012, tumor, treatment, endocrine, and auxological data of children with LGG were collected (n = 358). Prevalence and risk factors for elevated IGF-1 concentrations, as well as the association between having elevated IGF-1 concentrations and receiving tumor treatment, were explored. IGF-1 concentrations had only been measured in 45.5% of cases (n = 163/358). In 18.4% of 163 children with available IGF-1 measurements, IGF-1 concentrations were found elevated. No association was described between having an elevated IGF-1 concentration and tumor behavior or height SDS at last moment of follow-up. Multivariate logistic regression identified posterior pituitary disorder (OR 6.14 95% CI: 2.21-17.09) and BMI SDS at follow-up (OR 1.56 95% CI: 1.09-2.20) to be significantly associated with elevated IGF-1 concentrations. In this retrospective cohort of children with LGG, IGF-1 was found elevated in 18.4% of children with available IGF-1 measurements. Elevated IGF-1 seems to be related to hypothalamic dysfunction worsening over time. Larger prospective cohort studies are needed.

Treatment and outcome of the Dutch Childhood Craniopharyngioma Cohort study: First results after centralization of care.

BACKGROUND: Childhood craniopharyngioma (cCP) has excellent survival, but quality of life may be severely hampered by hypothalamic dysfunction. We aimed to evaluate treatment and hypothalamic outcomes of a Dutch cCP cohort, and evaluate the effect of centralization of care. METHODS: A retrospective cohort study was performed, including cCP patients diagnosed between 2004 and 2021. Treatment characteristics and hypothalamic outcomes were evaluated and compared before and since centralization of care in May 2018. RESULTS: We included 87 cCP patients. Cyst drainage/fenestration was performed in 29.9%, limited resection in 27.6%, near-total resection in 16.1%, and gross total resection (GTR) in 25.4%. Radiotherapy was given in 46.0%. After a median follow-up of 6.5 years, hypothalamic obesity (HO) was present in 24.7% and panhypopituitarism with diabetes insipidus in 71.3%. Higher body mass index (BMI) SDS at diagnosis and Muller grade II at last magnetic resonance imaging of follow-up were associated with overweight/obesity. No association was found between extensiveness of resection and overweight/obesity at last follow-up. When comparing before and after centralization of care, rates of GTR remained similar, but BMI outcomes changed; mean ΔBMI SDS 1 year after diagnosis from 1.12 (SD 1.15) to 0.81 (SD 1.24), and HO after 1 year decreased from 33.3% to 12.0% (P = .067), and after 2 years from 28.6% to 6.7% (P = NS). CONCLUSIONS: In our nationwide cohort, GTR was performed in a relatively low percentage of patients and extensiveness of resection was no longer associated with HO at follow-up. A trend toward improvement of BMI is observed since centralization of care, which needs further exploration.

Safety of Growth Hormone Replacement Therapy in Childhood-Onset Craniopharyngioma: A Systematic Review and Cohort Study.

INTRODUCTION: Survival of childhood-onset craniopharyngioma (cCP) is excellent; however, many survivors suffer from hypothalamic-pituitary dysfunction. Growth hormone replacement therapy (GHRT) is of high importance for linear growth and metabolic outcome. Optimal timing for initiation of GHRT in cCP is on debate because of concerns regarding tumor progression or recurrence. METHODS: A systematic review and cohort studys were performed for the effect and timing of GHRT on overall mortality, tumor progression/recurrence, and secondary tumors in cCP. Within the cohort, cCP receiving GHRT ≤1 year after diagnosis were compared to those receiving GHRT >1 year after diagnosis. RESULTS: Evidence of 18 included studies, reporting on 6,603 cCP with GHRT, suggests that GHRT does not increase the risk for overall mortality, progression, or recurrent disease. One study evaluated timing of GHRT and progression/recurrence-free survival and found no increased risk with earlier initiation. One study reported a higher than expected prevalence of secondary intracranial tumors compared to a healthy population, possibly confounded by radiotherapy. In our cohort, 75 of 87 cCP (86.2%) received GHRT for median of 4.9 years [0.0-17.1]. No effect of timing of GHRT was found on mortality, progression/recurrence-free survival, or secondary tumors. CONCLUSION: Although the quality of the evidence is low, the available evidence suggests no effect of GHRT or its timing on mortality, tumor progression/recurrence, or secondary neoplasms in cCP. These results support early initiation of GHRT in cCP aiming to optimize linear growth and metabolic outcome. Prospective studies are needed to increase the level of evidence upon the optimal timing to start GHRT in cCP patients.

Hormone replacement in survivors of childhood cancer and brain tumors: safety and controversies.

Childhood cancer survivors are at risk for developing endocrine disorders, including deficits in growth hormone, thyroid hormone and sex hormones. The influence these hormones have on cell growth and metabolism has raised concerns regarding the safety of their use as treatments in survivors of childhood cancer and brain tumors. This article offers a summary of current knowledge, controversies and areas for future research pertaining to this area.

Transition From Diencephalic Syndrome to Hypothalamic Obesity in Children With Suprasellar Low Grade Glioma: A Case Series.

Background: Children with suprasellar low grade glioma (LGG) frequently develop problems to maintain their body weight within the normal range, due to hypothalamic dysfunction. Hypothalamic damage may result in the diencephalic syndrome (DS), characterized by underweight or failure to thrive, but also in hypothalamic obesity (HO). Children with LGG presenting with DS at young age often develop HO later in life. The underlying pathophysiology for this change in body mass index (BMI) is not understood. Previous hypotheses have focused on the tumor or its treatment as the underlying cause. To better understand its etiology, we aimed to relate changes in BMI over time in children with suprasellar LGG presenting with DS to age, tumor progression, treatment, and endocrine function. We hypothesize that the development of HO in children with LGG presenting with DS is related to maturation status of the hypothalamus at time of injury and thus age. Methods: In this retrospective case series, all cases diagnosed in the Netherlands with suprasellar located LGG, currently treated or followed, with a history of DS developing into HO were included. Results: In total, 10 children were included. Median age at LGG diagnosis was 1.5 years (range 0.4-5.5), median BMI SDS was -2.64. The children developed overweight at a median age of 4.5 years (2.2-9.8). The median total difference in BMI SDS between underweight and obesity was +5.75 SDS (4.5-8.7). No association could be found between transition of DS to HO and onset of a pituitary disorder (present in 70.0%), surgery, chemotherapy, or tumor behavior. Two had developed central precocious puberty (CPP), both while having underweight or normal weight. Conclusion: The shift from DS to HO in children with hypothalamic LGG may be associated with age and not to tumor behavior, treatment characteristics or pituitary function. The development of CPP in these children seems not to be related to obesity. Our findings may indicate that the clinical picture of hypothalamic dysfunction reflects the maturation state of the hypothalamus at time of lesioning. Future prospective studies are needed to better understand underlying causative mechanisms of the morbid changes in body weight.

Dextroamphetamine Treatment in Children With Hypothalamic Obesity.

Introduction: Hypothalamic obesity (HO) in children has severe health consequences. Lifestyle interventions are mostly insufficient and currently no drug treatment is approved for children with HO. Amphetamines are known for their stimulant side-effect on resting energy expenditure (REE) and suppressing of appetite. Earlier case series have shown positive effects of amphetamines on weight in children with acquired HO. We present our experiences with dextroamphetamine treatment in the, up to now, largest cohort of children with HO. Methods: A retrospective cohort evaluation was performed of children with HO treated with dextroamphetamine at two academic endocrine pediatric clinics. Off-label use of dextroamphetamine was initiated in patients with progressive, therapy-resistant acquired or congenital HO. Anthropometrics, REE, self-reported (hyperphagic) behavior and energy level, and side effects were assessed at start and during treatment. Results: Nineteen patients with a mean age of 12.3 ± 4.0 years had been treated with dextroamphetamine. In two patients, ΔBMI SDS could not be evaluated due to short treatment duration or the simultaneous start of extensive lifestyle treatment. Mean treatment duration of the 17 evaluated patients was 23.7 ± 12.7 months. Fourteen patients (n = 10 with acquired HO, n = 4 with congenital HO) responded by BMI decline or BMI stabilization (mean ΔBMI SDS of -0.6 ± 0.8, after a mean period of 22.4 ± 10.5 months). In three patients, BMI SDS increased (mean ΔBMI SDS of +0.5 ± 0.1, after a mean period of 29.7 ± 22.6 months). In 11 responders, measured REE divided by predicted REE increased with +8.9%. Thirteen patients (68.4%) reported decreased hyperphagia, improvement of energy level and/or behavior during treatment. Two patients developed hypertension during treatment, which resulted in dosage adjustment or discontinuation of treatment. Twelve children continued treatment at last moment of follow-up. Conclusion: In addition to supportive lifestyle interventions, dextroamphetamine treatment may improve BMI in children with HO. Furthermore, dextroamphetamines have the potential to decrease hyperphagia and improve resting energy expenditure, behavior, and energy level. In patients with acquired HO, these effects seem to be more pronounced when compared to patients with congenital HO. Future studies are needed to support these results.

Serum hepcidin concentrations in relation to iron status in children with type 1 diabetes.

Chronic low-grade inflammation in type 1 diabetes (T1D) might increase hepcidin synthesis, possibly resulting in functional iron deficiency (FID). We hypothesized that in T1D children with FID, hepcidin concentrations are increased compared to those with normal iron status and those with absolute iron deficiency (AID). We evaluated hepcidin concentrations in T1D children in relation to iron status, and investigated whether hepcidin is useful in assessing FID. A cross-sectional study was conducted. FID was defined as elevated zinc protoporphyrin/heme ratio and/or red blood cell distribution width, and AID as low serum ferritin concentration. Post-hoc analyses with different definitions of FID were performed, using transferrin saturation and reticulocyte hemoglobin content. Serum hepcidin concentrations were measured using mass-spectrometry. The IRODIAB-study is registered at www.trialregister.nl (NTR4642). This study included 215 T1D children with a median age of 13.7 years (Q1-Q3: 10.1-16.3). The median (Q1-Q3) hepcidin concentration in patients with normal iron status was 1.8 nmol/l (0.9-3.3), in AID-patients, 0.4 nmol/l (0.4-0.4) and in FID-patients, 1.6 nmol/l (0.7-3.5). Hepcidin concentrations in FID-patients were significantly higher than in AID-patients (p < 0.001). Irrespective of FID-definition used, hepcidin concentrations did not differ between FID-patients and patients with normal iron status. This might be explained by the influence of various factors on hepcidin concentrations, and/or by differences in response of iron parameters over time. Single hepcidin measurements do not seem useful in assessing FID in T1D children. Multiple hepcidin measurements over time in future studies, however, might prove to be more useful in assessing FID in children with T1D.

Is mid-upper arm circumference in Dutch children useful in identifying obesity?

BACKGROUND: Mid-upper arm circumference (MUAC) is suggested as being a valid measure in detecting overweight/obesity in children and adolescents, due to the strong relation with weight. We examined this relation and compared MUAC to body mass index (BMI) according to the International Obesity Task Force (IOTF) in children. METHODS: Anthropometric data including MUAC were collected in 2009 by trained healthcare professionals in the context of the fifth Dutch Nationwide Growth Study, in a sample of 6167 children (2891 boys and 3276 girls) aged 2-18 years of Dutch origin. We propose MUAC SDS cut-off values for overweight and obesity, and compared MUAC with BMI IOTF in sex-specific and age-specific categories (2-5, 6-11, 12-18 years). RESULTS: The area under the curve is used as a measure of diagnostic accuracy; the explained variance (R²) is good to excellent (0.88-0.94). Sensitivity ranges from 51.8% to 95.3% and specificity from 71.4% to 93.8%. Across age and gender groups, 65.1% to 89.0% participants are classified by both MUAC and BMI as normal weight, overweight or obese. We constructed three equations to predict weight using MUAC, with small differences between observed and predicted weight with an explained variance ranging from 0.88 to 0.94. CONCLUSIONS: Compared with BMI, MUAC is a valid measure for detecting overweight and obesity and thus a good alternative for BMI. When weight has to be estimated, it can be accurately predicted using MUAC. Based on our observations, we recommend developing diagrams with international (IOTF) cut-offs for MUAC SDS similar to BMI.

[A toddler with a rare complication of scarlet fever]. / Een peuter met een zeldzame complicatie van roodvonk.

BACKGROUND: Haemolytic group A streptococci (GAS) are the most common bacterial cause of infection in the Netherlands. These bacteria can cause many different non-invasive infections, including scarlet fever. CASE DESCRIPTION: A two-year-old girl presented with fever, tachycardia, exanthema and swelling in the neck. On suspicion of scarlet fever with neck phlegmon we treated her with antibiotics and supportive therapy. Blood and throat cultures revealed growth of haemolytic GAS. Lab tests revealed mild hyperthyroidism and neck ultrasound revealed an inhomogeneous appearance of the thyroid. We diagnosed her with 'infectious thyroiditis', a rare complication of infection with haemolytic GAS. A fistula from the pyriform sinus could not be demonstrated. CONCLUSION: Although GAS infections are common, complications such as thyroiditis are rare. When a paediatric patient is diagnosed with infectious thyroiditis, a fistula from the pyriform sinus should be considered. Patients with such a congenital malformation have an increased risk of recurrent infectious thyroiditis and thyroid abscess formation.

Mutations in IRS4 are associated with central hypothyroidism.

BACKGROUND: Four genetic causes of isolated congenital central hypothyroidism (CeH) have been identified, but many cases remain unexplained. We hypothesised the existence of other genetic causes of CeH with a Mendelian inheritance pattern. METHODS: We performed exome sequencing in two families with unexplained isolated CeH and subsequently Sanger sequenced unrelated idiopathic CeH cases. We performed clinical and biochemical characterisation of the probands and carriers identified by family screening. We investigated IRS4 mRNA expression in human hypothalamus and pituitary tissue, and measured serum thyroid hormones and Trh and Tshb mRNA expression in hypothalamus and pituitary tissue of Irs4 knockout mice. RESULTS: We found mutations in the insulin receptor substrate 4 (IRS4) gene in two pairs of brothers with CeH (one nonsense, one frameshift). Sequencing of IRS4 in 12 unrelated CeH cases negative for variants in known genes yielded three frameshift mutations (two novel) in three patients and one male sibling. All male carriers (n=8) had CeH with plasma free thyroxine concentrations below the reference interval. MRI of the hypothalamus and pituitary showed no structural abnormalities (n=12). 24-hour thyroid-stimulating hormone (TSH) secretion profiles in two adult male patients showed decreased basal, pulsatile and total TSH secretion. IRS4 mRNA was expressed in human hypothalamic nuclei, including the paraventricular nucleus, and in the pituitary gland. Female knockout mice showed decreased pituitary Tshb mRNA levels but had unchanged serum thyroid hormone concentrations. CONCLUSIONS: Mutations in IRS4 are associated with isolated CeH in male carriers. As IRS4 is involved in leptin signalling, the phenotype may be related to disrupted leptin signalling.

Iron status and its association with HbA1c levels in Dutch children with diabetes mellitus type 1.

Children with diabetes mellitus (DM) type 1 may be at risk for iron deficiency (ID) although this has been little studied. ID is either an absolute (depleted iron stores) or a functional (restricted iron stores due to chronic inflammation) deficiency each requiring a different therapeutic approach. Unfortunately, absolute ID is often not distinguished from functional ID. Furthermore, iron-deficient anemia may influence hemoglobin A1c (HbA1c) levels. We aimed to determine the prevalence and type of ID and investigate its association with HbA1c levels in pediatric DM type 1 patients. We performed a two-center prospective observational study in which the iron status of Dutch children with DM type 1 was determined during a regular check-up. Absolute ID and functional ID were found in 13/227 (5.7%) and 100/214 (47%) patients, respectively, while only 15/113 (13%) patients also had anemia. HbA1c levels in patients with and without a deprived iron status (absolute or functional) were not significantly different (65 ± 17 vs. 65 ± 16 mmol/mol, p = 0.815). CONCLUSION: Functional, but not absolute, ID was common in Dutch pediatric DM type 1 patients. HbA1c levels were not associated with ID, which can be explained by the relatively mild deprived iron status in our patients. TRIAL REGISTRATION: NTR4642 What is Known: • Iron deficiency is either an absolute (depleted iron stores) or a functional (restricted iron stores due to chronic inflammation) deficiency each requiring a different therapeutic approach. • Children with diabetes mellitus type 1 may be at risk for both types of iron deficiency and this can influence their hemoglobin A1c levels although this has been little studied. What is New: • In Dutch children with diabetes mellitus type 1, functional, but not absolute iron deficiency, is common and should not be treated with iron replacement therapy. • Hemoglobin A1c levels were not associated with iron deficiency, probably due to the relatively mild deprived iron status in our patients.

A Girl With Beckwith-Wiedemann Syndrome and Pseudohypoparathyroidism Type 1B Due to Multiple Imprinting Defects.

CONTEXT: Several patients with Beckwith-Wiedemann Syndrome (BWS) with multiple imprinting defects found by genetic analysis have been described. However, only two cases have been described with both genetic and clinical signs and symptoms of multiple diseases caused by imprinting defects. CASE DESCRIPTION: The girl in this case presented at the age of 6 months with morbid obesity (body mass index, +7.5 SDS) and a large umbilical hernia. Genetic analysis showed BWS (hypomethylation of the KCNQ1OT1 gene). Calcium homeostasis was normal, and she had no signs of Albright hereditary osteodystrophy. At the age of 10 years, she presented with fatigue, and laboratory analyses showed marked hypocalcemia with signs of PTH resistance, but without evidence for Albright hereditary osteodystrophy, thus suggesting pseudohypoparathyroidism type 1B. Consistent with this diagnosis, methylation analysis of the GNAS complex revealed hypomethylation (about 20%) of the GNAS exon 1A, NESPAS, and GNASXL loci and hypermethylation (100% methylation) of the NESP locus. CONCLUSIONS: Imprinting defects at several different loci can occur in some patients, thus causing multiple different diseases. Symptoms of pseudohypoparathyroidism type 1B may be absent at diagnosis of BWS, yet prolonged subclinical hypocalcemia and/or hyperphosphatemia can have negative consequences (eg, intracerebral calcifications, myocardial dysfunction). We therefore suggest that patients with an imprinting disorder should be monitored for elevations in PTH, and epigenetic analysis of the GNAS complex locus should be considered.

Trends in menarcheal age between 1955 and 2009 in the Netherlands.

AIM: To assess and compare the secular trend in age at menarche in Dutch girls (1955-2009) and girls from Turkish and Moroccan descent living in the Netherlands (1997-2009). METHODS: Data on growth and maturation were collected in 20,867 children of Dutch, Turkish and Moroccan descent in 2009 by trained health care professionals. Girls, 9 years and older, of Dutch (n = 2138), Turkish (n = 282), and Moroccan (n = 295) descent were asked whether they had experienced their first period. We compared median menarcheal age in 2009 with data from the previous Dutch Nationwide Growth Studies in 1955, 1965, 1980 and 1997. Age specific body mass index (BMI) z-scores were calculated to assess differences in BMI between pre- and postmenarcheal girls in different age groups. RESULTS: Median age at menarche in Dutch girls, decreased significantly from 13.66 years in 1955 to 13.15 years in 1997 and 13.05 years in 2009. Compared to Dutch girls there is a larger decrease in median age of menarche in girls of Turkish and Moroccan descent between 1997 and 2009. In Turkish girls age at menarche decreased from 12.80 to 12.50 years and in Moroccan girls from 12.90 to 12.60 years. Thirty-three percent of Turkish girls younger than 12 years start menstruating in primary school. BMI-SDS is significantly higher in postmenarcheal girls than in premenarcheal girls irrespective of age. CONCLUSION: There is a continuing secular trend in earlier age at menarche in Dutch girls. An even faster decrease in age at menarche is observed in girls of Turkish and Moroccan descent in the Netherlands.

The world's tallest nation has stopped growing taller: the height of Dutch children from 1955 to 2009.

BACKGROUND: Records show that mean height in The Netherlands has increased since 1858. This study looks at whether this trend in the world's tallest nation is continuing. We consider the influence of the geographical region, and of the child and parental education, on changes in height. METHODS: We compared the height of young Dutch people aged 0-21 y as determined on the basis of the growth study of 2009, with the height data from growth studies conducted in 1955, 1965, 1980, and 1997. RESULTS: The analysis sample included 5,811 boys and 6,194 girls. Height by age was the same as in 1997. Mean final height was 183.8 cm (SD = 7.1 cm) in boys and 170.7 cm (SD = 6.3 cm) in girls. The educational levels of both children and their parents are positively correlated with mean height. Since 1997, differences between geographical regions have decreased but not vanished, with the northern population being the tallest. CONCLUSION: The world's tallest population has stopped growing taller after a period of 150 y, the cause of which is unclear. The Dutch may have reached the optimal height distribution. Alternatively, growth-promoting environmental factors may have stabilized in the past decade, preventing the population from attaining its full growth potential.

Absence of clinically relevant growth acceleration in untreated children with non-classical congenital adrenal hyperplasia.

BACKGROUND/AIMS: In classical congenital adrenal hyperplasia (CAH), elevation of adrenal androgens leads to accelerated growth and bone maturation with compromised adult height. In untreated children with non-classical CAH (NC-CAH), in which adrenal androgens are generally only slightly increased, growth velocity may not be significantly elevated. METHODS: Twenty-four patients were included and divided into a symptomatic and an asymptomatic group. Height was expressed as height standard deviation scores (HSDS) and corrected for target height (HSDS-THSDS). Bone maturation was expressed as bone age acceleration (BA(c) = bone age - calendar age). Linear mixed models with random factor patient were used for the analysis of growth and bone age. RESULTS: In symptomatic patients (n = 17), HSDS-THSDS only slightly increased by 0.06 SDS per year (95% CI 0.02-0.10). Mean BA(c) was 2.21 years (SDS 0.66, p < 0.0001). In asymptomatic patients (n = 7), no significant growth acceleration or BA(c) was found. CONCLUSIONS: In untreated NC-CAH children, growth acceleration is small and generally not visible on their growth charts. BA(c) is more pronounced. Therefore, the absence of an increase in growth velocity does not exclude the diagnosis of NC-CAH. When considering this diagnosis, bone age acceleration should also be taken into account.

Increase in prevalence of overweight in Dutch children and adolescents: a comparison of nationwide growth studies in 1980, 1997 and 2009.

OBJECTIVE: To assess the prevalence of overweight and obesity among Dutch children and adolescents, to examine the 30-years trend, and to create new body mass index reference charts. DESIGN: Nationwide cross-sectional data collection by trained health care professionals. PARTICIPANTS: 10,129 children of Dutch origin aged 0-21 years. MAIN OUTCOME MEASURES: Overweight (including obesity) and obesity prevalences for Dutch children, defined by the cut-off values on body mass index references according to the International Obesity Task Force. RESULTS: In 2009, 12.8% of the Dutch boys and 14.8% of the Dutch girls aged 2-21 years were overweight and 1.8% of the boys and 2.2% of the girls were classified as obese. This is a two to three fold higher prevalence in overweight and four to six fold increase in obesity since 1980. Since 1997, a substantial rise took place, especially in obesity, which increased 1.4 times in girls and doubled in boys. There was no increase in mean BMI SDS in the major cities since 1997. CONCLUSIONS: Overweight and obesity prevalences in 2009 were substantially higher than in 1980 and 1997. However, the overweight prevalence stabilized in the major cities. This might be an indication that the rising trend in overweight in The Netherlands is starting to turn.

The jumping SHOX gene--crossover in the pseudoautosomal region resulting in unusual inheritance of Leri-Weill dyschondrosteosis.

CONTEXT: During meiosis I, the recombination frequency in the pseudoautosomal region on Xp and Yp (PAR1) in males is very high. As a result, mutated genes located within the PAR1 region can be transferred from the Y-chromosome to the X-chromosome and vice versa. PATIENTS: Here we describe three families with SHOX abnormalities resulting in Leri-Weill dyschondrosteosis or Langer mesomelic dysplasia. RESULTS: In about half of the segregations investigated, a transfer of the SHOX abnormality to the alternate sex chromosome was demonstrated. CONCLUSIONS: Patients with an abnormality of the SHOX gene should receive genetic counseling as to the likelihood that they may transmit the mutation or deletion to a son as well as to a daughter.