Extreme phenotypic variability of thyroid dysgenesis in six new cases of congenital hypothyroidism due to PAX8 gene loss-of-function mutations

CONTEXT

Within the last two decades, heterozygous loss-of-function PAX8 mutations have been reported in patients with a wide degree of thyroid gland dysfunction and growth despite the presence of identical mutations.

OBJECTIVES

To search for PAX8 mutations in a cohort of patients with congenital hypothyroidism (CH) and various types of thyroid gland defects.

DESIGN

A cross-sectional study was conducted in a cohort of patients.

SETTING

The French neonatal screening program was used for recruiting patients.

PATIENTS

A total of 118 patients with CH, including 45 with familial and 73 with sporadic diseases, were included in this study. The thyroid gland was normal in 23 patients had hypoplasia, 25 had hemithyroid agenesis, 21 had athyreosis, and 21 had ectopy.

RESULTS

We found four different PAX8 mutations (p.R31C, p.R31H, p.R108X, and p.I47T) in ten patients (six patients with CH and four family members), two with sporadic and eight with familial diseases. Imaging studies performed in the index cases showed ectopic thyroid gland (n=2), hypoplasia (n=2), eutopic lobar asymmetry (n=1), and eutopic gland compatible with dyshormonogenesis (n=1). The previously reported p.R31C and the novel p.I47T PAX8 mutations are devoid of activity.

CONCLUSION

Four different PAX8 mutations were detected in six index patients with CH (ten total subjects). The p.R31C, p.R31H, and p.R108X mutations have been reported. The novel p.I47T PAX8 mutation presented loss of function leading to CH. Thyroid ectopy was observed in two cases of PAX8 (p.R31H) mutation, a finding that has not been reported previously. We observed a high inter-individual and intra-familial variability of the phenotype in PAX8 mutations, underlining that population genetic studies for CH should include patients with various clinical presentations.

Evolution of IGF-1 in children born small for gestational age and with growth retardation, treated by growth hormone adapted to IGF-1 levels after 1 year

AIM

This study was designed to estimate the percentage of growth hormone (GH)-treated children born small for gestational age (SGA), with serum IGF-1 >2 SDS before and after GH dose adaptation.

METHODS

SGA boys aged 4-9 and girls aged 4-7 with a height <-2 SDS and an annual growth rate below the mean received a subcutaneous GH dose of 57 μg/kg/day for 2 years. The GH dose was to be decreased by 30% in children with serum IGF-1 >2 SDS at 12 months and on the previous sample. The GH dose could be reduced a second time to 35 μg/kg·day. IGF-1 and IGFBP-3 dosages were centralized.

RESULTS

Among the 49 (21 boys) children included in the study, 8 (16.3%) had an IGF-1 >2 SDS consecutively at 9 and 12 months (95% CI 7.3, 29.7). The GH dose was decreased in 6/8 children. However, IGF-1 levels were elevated at several nonconsecutive determinations in 45% (95% CI 28.4, 56.6) of the patients.

CONCLUSION

A high IGF-1 level is observed in 45% of the GH SGA-treated children with a relatively high dose of GH. A 30% reduction in the GH dose causes a decrease in IGF-1 below 2 SDS in most children.

Growth hormone treatment before the age of 4 years prevents short stature in young girls with Turner syndrome

OBJECTIVE

Adult height deficit seen in Turner syndrome (TS) originates, in part, from growth retardation in utero and throughout the first 3 years of life. Earlier diagnosis enables earlier therapeutic intervention, such as with recombinant human GH (r-hGH), which may help to prevent growth retardation. In this open-label, multicentre phase III study, we investigated efficacy and safety in r-hGH treatment in young girls with TS.

SUBJECTS AND METHODS

Girls (n=61) aged <4 years with TS receiving 0.035-0.05 mg/kg per day r-hGH for 4 years were compared with an historical control group (n=51) comprising untreated, age- and height-matched girls with TS. The main outcome measure was change in height SDS (H-SDS). Other measures included changes in height velocity SDS, IGF1 levels and glucose metabolism.

RESULTS

After 4 years, a gain in mean H-SDS of 1.0 SDS (from -2.33±0.73 to -1.35±0.86 SDS) was observed with r-hGH treatment, in contrast to the decrease in mean H-SDS of 0.3 SDS in the control group (from -2.09±0.81 to -2.44±0.73 SDS; P<0.0001). r-hGH treatment was the main predictor of H-SDS gain and accounted for 52% of variability (multivariate analysis). r-hGH was well tolerated. As expected, IGF1 levels rose with treatment. A case of transient glucose intolerance resolved after dietary adaptation.

CONCLUSION

Early treatment with r-hGH helps to prevent natural evolution towards short stature in most girls with TS. IGF1 levels and glucose metabolism should be monitored routinely during r-hGH therapy.

Management of Wilms tumors in Drash and Frasier syndromes

BACKGROUND

Children with WT1 gene-related disorders such as Denys-Drash syndrome (DDS) and Frasier syndrome (FS) are at increased risk of Wilms tumor and end-stage renal disease. We investigated whether Wilms tumors in these patients displayed a specific phenotype or behavior and whether nephron-sparing surgery was beneficial.

PROCEDURE

We retrospectively studied all patients with DDS, FS, or other WT1 mutations treated at our institutions between 1980 and 2007.

RESULTS

We identified 20 patients, of whom 18 had benign or malignant tumors. Wilms tumors occurred in 15 patients, being unilateral in 10 and bilateral in 5 (20 tumors). Median age at Wilms tumor diagnosis was 9 months. No patients had metastases. According to the International Society of Pediatric Oncology Working Classification, there were 19 intermediate-risk tumors and one high-risk tumor; no tumor was anaplastic. In patients with nephropathy who underwent unilateral nephrectomy for Wilms tumor or nephron-sparing surgery for bilateral Wilms tumor, mean time to dialysis was 11 or 9 months, respectively. Other tumors included three gonadoblastomas (in two patients), one retroperitoneal soft-tissue tumor, and one transitional cell papilloma of the bladder. Two patients, both with stage I Wilms tumor, died from end-stage renal disease-related complications. The median follow-up time for the 18 survivors was 136 months (range, 17-224 months).

CONCLUSION

Most Wilms tumors in children with WT1-related disorders were early-stage and intermediate-risk tumors, with a young age at diagnosis. In patients without end-stage renal disease, nephron-sparing surgery should be considered for delaying the onset of renal failure.

Hypertension pulmonaire postembolique

INTRODUCTION

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease characterized by the persistence of thromboemboli obstructing the pulmonary arteries as an organized tissue. The consequence is an increase in pulmonary vascular resistance resulting in pulmonary hypertension (PH) and progressive right heart failure.

BACKGROUND

It is difficult to recognize the postembolic nature of PH because there is no known history of thromboembolic disease in more than 50% of cases. Diagnosis is based on the presence of mismatched segmental defects in the ventilation-perfusion scanning. When CTEPH is suspected, pulmonary angiography and high-resolution CT scan are required to establish the diagnosis and to assess the operability. Pulmonary angiography is always performed in conjunction with a diagnostic right heart catheterization, which is required to confirm the diagnosis of PH and to determine the degree of hemodynamic impairement. If there is a good correlation between the pulmonary vascular resistance and the anatomical obstruction, pulmonary endarterectomy (PEA) must be proposed. Otherwise, vasodilator and antiproliferative treatments and lung transplantation represent interesting alternatives.

VIEWPOINT AND CONCLUSION

PEA remains the treatment of choice for eligible patients. Nevertheless, there is a need to conduct randomized trials to assess the efficacy of novel medical therapies in some situations: (1) in inoperable CTEPH due to distal lesions, (2) before PEA (therapeutic bridge) in patients who are considered "high risk" due to extremely poor hemodynamics, (3) in patients with persistent pulmonary hypertension after surgery.

Le syndrome de Turner☆☆Cet article est publié en partenariat avec Orphanet et disponible sur le site www.orpha.net. © 2007 Orphanet. Publié par Elsevier Masson SAS. Tous droits réservés

Turner syndrome occurs in 1:5000 live births (1:2,500 females) and is caused not only by X-chromosome monosomy, but also in a large degree, by the presence of a mosaicism (45,X) and/or an abnormal X or Y chromosome (deletion, isochromosome X, dicentric chromosome). Clinical features are heterogeneous and typical physical anomalies are often mild or absent. In all cases, patients are short but final height has been improved by growth hormone therapy. Ovarian failure, with variable onset depending on the chromosomal anomalies, is frequent. Others visceral diseases (bone anomalies, lymphedema, deafness, and cardiovascular, thyroid, gastrointestinal diseases) are less common and need a screening at diagnosis, then a survey during adolescence and adulthood. During gestation, typical forms can be diagnosed by ultrasound examination, but mild forms are discovered incidentally during amniocentesis for unrelated reasons (advanced maternal age) and prenatal advice is difficult. The quality of life and social life is better when puberty is not induced too late, and in absence of cardiac disease or deafness. Deafness can lead to learning difficulties and, during adulthood, sterility can have a negative effect on quality of life. The prognosis depends on heart diseases, obesity, arterial hypertension and osteoporosis. Therefore, a long-term follow-up is necessary.

Bilateral anorchia in infancy: occurence of micropenis and the effect of testosterone treatment

OBJECTIVE

To analyze the clinical and histological findings in boys with bilateral anorchia and the response to testosterone treatment on penis length.

STUDY DESIGN

Patients were divided into two groups according to the absence (group A, n = 29) or the presence (group B, n = 26) of palpable intrascrotal or inguinal mass at first clinical examination.

RESULTS

A micropenis was found in 46% of patients (n = 24) with a similar proportion in both groups. Testosterone treatment induced a mean penis length gain of 1.9 +/- 1.3 SDS (standard deviation score). However, micropenis persisted in six patients. Histological examination (n = 18) confirmed the absence of any testicular structure with deferent ducts being present unilaterally or bilaterally in all but three patients. In these three patients, a hemorrhagic testis, probably as a result of a mechanical torsion, was found.

CONCLUSIONS

The presence of isolated micropenis in almost half of patients with bilateral anorchia strongly suggests that the testicular damage frequently occurs during the second half of gestation after male sexual differentiation. In most cases, testosterone treatment stimulates the penile growth. Although the pathogenesis of bilateral anorchia may be heterogeneous, our study suggests that gonads may have been functionally abnormal before they disappeared, and suggests that some patients have an intrinsic endocrine disorder.

Traitement de l’hypertension artérielle pulmonaire

Pulmonary arterial hypertension (PAH) is characterized by vasoconstriction, in situ thrombosis, and vascular remodeling of small pulmonary arteries. It induces a fixed pulmonary arterial obstruction, persistent elevation of pulmonary arterial resistance, and eventually right heart failure. Conventional therapy is based on simple measures (exercise limitation) and nonspecific treatments (warfarin, diuretics, and oxygen). Pure vasodilators, such as calcium channel blockers, are effective only in a minority of patients who have an acute response to vasodilator testing. Intravenous prostacyclin (epoprostenol) and endothelin receptor blockers have vasodilator and antiproliferative properties. Epoprostenol therapy has significantly improved PAH prognosis and remains the first-line treatment for patients with the most severe disease. Bosentan is an interesting first-line treatment for NYHA functional class III patients. Availability of novel specific drugs (endothelin receptor type A antagonists, prostacyclin analogues, type 5 phosphodiesterase inhibitors) is opening new perspectives in PAH treatment. The long-term benefit of these drugs remains to be evaluated and their respective place in treatment of these patients is still uncertain. The evolution of therapy from vasodilators to antiproliferative agents reflects the advancement in our understanding of the mechanisms mediating pulmonary arterial hypertension.

CHARGE syndrome includes hypogonadotropic hypogonadism and abnormal olfactory bulb development

CONTEXT

CHARGE (coloboma, heart defect, choanal atresia, retarded growth and development, genital hypoplasia, ear abnormalities, and/or hearing loss defect) syndrome consists of a combination of congenital malformations including genital hypoplasia and retarded growth.

OBJECTIVE

The objective of the study was to study gonadotropic axis function and growth parameters in CHARGE syndrome.

DESIGN

This was a retrospective study.

PATIENTS

The study included 32 children with CHARGE syndrome.

RESULTS

Nineteen of 20 affected boys had micropenis and/or cryptorchidism, consistent with hypogonadotropic hypogonadism during fetal life. None of the boys was of pubertal age. Seven of nine boys tested before the age of 5 months during the neonatal peak period had extremely low testosterone levels. LH response to GnRH stimulation was variable during the first year of life and not correlated with existing clinical abnormalities. None of the girls over the age of 12 yr (n = 7) had begun puberty spontaneously, and a lack of response to GnRH stimulation was documented in five of them. Olfactory evaluation (n = 10) and magnetic resonance imaging (n = 18) of the forebrain revealed defective sense of smell and abnormal olfactory bulbs in all cases. Cardiorespiratory and nutritional problems were corrected, but the mean height of the 25 children who had reached 5 yr of age was -2 +/- 0.2 sd score. Height was not correlated with birth length or body mass index. GH deficiency was diagnosed in only three children.

CONCLUSION

These findings suggest that CHARGE syndrome includes the main features of Kallmann syndrome, which is defined by hypogonadotropic hypogonadism combined with a defective sense of smell and abnormal olfactory bulb development. This forebrain abnormality, if confirmed in a larger group of patients, could serve as a major new criterion for the diagnosis of CHARGE syndrome.

IGF type 1 receptor ligand binding characteristics are altered in a subgroup of children with intrauterine growth retardation

The IGFs, IGF-I and IGF-II, regulate fetal growth by activating IGF type 1 receptors (IGF-IR). We aimed to quantify the binding of IGF-I to its cognate receptors in intrauterine growth-retarded children (IUGR). We measured the affinity of the erythrocyte IGF-IR and the number of IGF-IR receptors in 17 children with retarded growth (mean height, -2.7 SD), normal levels of GH, and a history of idiopathic intrauterine growth retardation (height at birth, -10 to -2 SD; mean, -3.1 SD). These children had reduced receptor affinity (Kd = 0.47 nM; P < 0.01) and more receptors per cell [binding capacity (Bmax) = 11.7 binding sites/cell; P < 0.05)] compared with control children (Kd = 0.32 nM; Bmax = 7.8 binding sites/cell). Moreover, the distributions of Kd and Bmax suggested that there were two groups of IUGR children. Group 1 included subjects with normal receptor binding function (Kd = 0.36 nM; Bmax = 8.2 sites/cell) and normal levels of circulating IGF-I. Group 2 comprised children with low receptor affinity (Kd = 0.56 nM) and increased receptor number (Bmax = 14.7 sites/cell). This group showed significantly decreased IGF-I levels (-2.1 SD; P < 0.01). We investigated these IGF-IR binding parameters in two additional groups of growth-retarded children (Turner syndrome and patients with chronic renal failure), in whom the IGF-I axis was not believed to be the primary cause, and found that Kd and Bmax were normal or nearly normal. We also measured IGF-IR binding parameters in 4 Seckel syndrome patients with IUGR and severely retarded growth (mean height, -7.9 SD). Their receptor affinity was reduced, but not statistically different, from that in controls, and their receptor number was normal, whereas IGF-I levels were elevated. Our results suggest heterogeneous alterations in IGF-IR binding function in IUGR patients.

[Massive hemoptysis during sarcoidosis]

Hemoptysis is a rare but often severe event in sarcoidosis. It usually occurs in patients with advanced, fibrotic lung disease. We herein report the case of a 36-year old female patient with type II pulmonary sarcoidosis who presented with abundant hemoptysis very early during the course of her disease. Two attempts to embolize bronchial arteries remained unsuccessful and surgery was eventually required to stop the bleeding. Clinical, microbiological, radiological and pathological data indicate that haemoptysis was caused by systemic hypervascularization around sarcoidosis granuloma.

Insulin-like growth factor-I (IGF-I), insulin-like growth factor binding proteins (IGFBP) and insulin-like growth factor type I receptor in children with various status of chronic renal failure

Chronic renal failure in childhood causes severe growth retardation. The aim of the study was to identify whether changes in the IGF system could account for the growth retardation observed in children with chronic renal failure. Insulin-like growth factor (IGF-I) serum concentrations, insulin-like growth factor binding proteins (IGFBP) and/or IGF-I binding to erythrocyte type I receptor of IGF were analysed in 69 children (mean age 11.6 +/- 4.3 years) with chronic renal failure and growth retardation (mean height -2.6 +/- 1.8 SD). The study population was separated into three groups, according to their renal status, children on conservative treatment (CRF group: n = 30), on haemodialysis (ESRD group: n = 26) and those transplanted (RT group: n = 13). Nineteen of these children, some from each of the three groups, received recombinant growth hormone therapy (rhGH). Mean basal IGF-I serum concentrations were -0.7 +/- 1.2 SD in the CRF group, + 2.1 +/- 3 SD in the ESRD group and + 1.1 +/- 2 SD in the RT group. Under rhGH therapy, as height velocity improved, mean IGF-I concentrations increased up to + 3.1 +/- 0.6 SD in the CRF group, to + 6.9 +/- 2.8 SD in the ESRD group and to + 3.9 +/- 2 SD in the RT group. Basal IGFBP-3 levels, studied by Western Ligand Blot were low in the CRF group and high in the ESRD and normal in the RT groups, whereas IGFBP-2 and a 30-32 kDa IGFBP were always high in all cases. Western immunoblot analysis showed that this 30-32 kDa IGFBP was mostly composed of IGFBP-1 and IGFBP-6 in all three groups, but IGFBP-6 was particularly abundant in the ESRD group. IGFBP-6 concentrations assessed by RIA were moderately increased in CRF children (392 +/- 177 ng/mL) and very high in children on ESRD (2094 +/- 1525 ng/mL) when compared to normal values (131 +/- 42 ng/mL). Binding studies of IGF type I receptor showed that there was no particular difference in IGF-I binding between renal failure patients and normal children. In poorly growing children, especially in ESRD children and to a lesser extent in RT children, high concentrations of IGF-I and IGFBP-1, 2, 3 and 6, suggest a resistance mainly by a sequestration mechanism. Moreover, in the CRF group, especially in the younger children, low levels of IGF-I and IGFBP-3 are evocative of an associated resistance at the GH receptor level.

[Physiopathology of the somatotropin axis in chronic renal insufficiency]

Many factors contribute to the growth failure of chronic renal failure: water and electrolytes disturbances, hypertonicity, phosphate or calcium wasting, secondary hyperparathyroidism, anemia, hypertension, metabolic acidosis, and malnutrition. In addition, the pubertal growth spurt is usually stunted. Growth hormone (GH) resistance is observed with low GH binding protein (GHBP) level, and normal or low IGF I levels despite elevated GH level. Elevated IGFBP levels may contribute to a reduced IGF activity, especially in dialysed patients. Glucocorticoid therapy in transplanted patients further contribute to poor growth and inhibited IGF I activity. As conventional treatments have a limited effect to improve growth, adult height is often far below -2 SD. GH therapy has proved to be successful, especially in young children, overpassing the hormonal resistance so that an adult height within the normal range may be reached.

New insight into the molecular basis of 3beta-hydroxysteroid dehydrogenase deficiency: identification of eight mutations in the HSD3B2 gene eleven patients from seven new families and comparison of the functional properties of twenty-five mutant enzymes

Classical 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase (3betaHSD) deficiency is a form of congenital adrenal hyperplasia that impairs steroidogenesis in both the adrenals and gonads resulting from mutations in the HSD3B2 gene and causing various degrees of salt-wasting in both sexes and incomplete masculinization of the external genitalia in genetic males. To identify the molecular lesion(s) in the HSD3B2 gene in the 11 patients from the seven new families suffering from classical 3betaHSD deficiency, the complete nucleotide sequence of the whole coding region and exon-intron splicing boundaries of this gene was determined by direct sequencing. Five of these families were referred to Morel's molecular diagnostics laboratory in France, whereas the two other families were investigated by Peter's group in Germany. Functional characterization studies were performed by Simard's group in Canada. Following transient expression in 293 cells of each of the mutant recombinant proteins generated by site-directed mutagenesis, the effect of the 25 mutations on enzyme activity was assessed by incubating intact cells in culture with 10 nM [14C]-DHEA as substrate. The stability of the mutant proteins has been investigated using a combination of Northern and Western blot analyses, as well as an in vitro transcription/translation assay using rabbit reticulocyte lysates. The present report describes the identification of 8 mutations, in seven new families with individuals suffering from classical 3betaHSD deficiency, thus increasing the number of known HSD3B2 mutations involved in this autosomal recessive disorder to 31 (1 splicing, 1 in-frame deletion, 3 nonsense, 4 frameshift and 22 missense mutations). In addition to the mutations reported here in these new families, we have also investigated for the first time the functional significance of previously reported missense mutations and or sequence variants namely, A82T, A167V, L173R, L205P, S213G and K216E, P222H, T259M, and T259R, which have not previously been functionally characterized. Furthermore, their effects have been compared with those of the 10 previously reported mutant enzymes to provide a more consistent and comprehensive study. The present results are in accordance with the prediction that no functional 3betaHSD type 2 isoenzyme is expressed in the adrenals and gonads of the patients suffering from a severe salt-wasting form of CAH due to classical 3betaHSD deficiency. Whereas the nonsalt-losing form also results from missense mutation(s) in the HSD3B2 gene, which cause an incomplete loss in enzyme activity, thus leaving sufficient enzymatic activity to prevent salt wasting. The functional data described in the present study concerning the sequence variants A167V, S213G, K216E and L236S, which were detected with premature pubarche or hyperandrogenic adolescent girls suspected to be affected from nonclassical 3betaHSD deficiency, coupled with the previous studies reporting that no mutations were found in both HSD3B1 and/or HSD3B2 genes in such patients strongly support the conclusion that this disorder does not result from a mutant 3betaHSD isoenzyme. The present study provides biochemical evidence supporting the involvement of a new molecular mechanism in classical 3betaHSD deficiency involving protein instability and further illustrates the complexity of the genotype-phenotype relationships of this disease, in addition to providing further valuable information concerning the structure-function relationships of the 3betaHSD superfamily.

Anxiety and depressive disorders in fathers and mothers of anxious school-refusing children

OBJECTIVE

To examine anxiety and depressive disorders in the mothers and fathers of children with anxious school refusal and to test for the existence of differences in familial aggregation between children suffering from school refusal related to separation anxiety disorder and those suffering from phobic disorder-based school refusal.

METHOD

Using a blind standardized diagnostic evaluation (Schedule for Affective Disorders and Schizophrenia-Lifetime version, modified for the study of anxiety disorders; Diagnostic Interview for Genetic Studies; and Schedule for Affective Disorders and Schizophrenia for School-Age Children), the authors compared parental lifetime psychiatric illness for the 2 groups of anxious school refusers.

RESULTS

Relationships between specific anxiety disorders in children and their parents revealed increased prevalence of simple phobia and simple and/or social phobia among the fathers and mothers of phobic school refusers, and increased prevalence of panic disorder and panic disorder and/or agoraphobia among the fathers and mothers of school refusers with separation anxiety disorder. Simple and/or social phobia in the father, simple phobia in the mother, and age of the father were associated with the group of phobic school refusers.

CONCLUSIONS

The data show the high prevalence of both anxiety and depressive disorders in fathers and mothers of anxious school refusers. Significant differences were observed in familial aggregation considering the subgroups of anxious school-refusing children.

[Myocardiopathy and isolated glucocorticoid deficit with ACTH resistance: a fortuitous association?]

Hereditary syndrome of unresponsiveness to ACTH is a rare autosomal recessive disorder characterized by an isolated glucocorticoid deficiency which is exceptionally associated to regressive cardiomyopathy.

CASE REPORT

A male newborn had iterative episodes of hypoglycemia since the first hours of life. Acute bronchiolitis at the age of 14 days was associated with transitory dilated cardiomyopathy. Hypoglycemia was due to glucocorticoid deficiency secondary to ACTH insensitivity. Molecular biology showed a composite heterozygotism for the ACTH receptor gene.

CONCLUSION

Any congenital glucocorticoid deficiency should lead to search for cardiomyopathy.

Evaluation of gonadal function in 107 intersex patients by means of serum antimüllerian hormone measurement

Fetal male sexual differentiation is driven by two testicular hormones: testosterone (synthesized by interstitial Leydig cells) and antimüllerian hormone (AMH; produced by Sertoli cells present in the seminiferous tubules). Intersex states result either from gonadal dysgenesis, in which both Leydig and Sertoli cell populations are affected, or from impaired secretion or action of either testosterone or AMH. Until now, only Leydig cell function has been assessed in children with ambiguous genitalia, by means of testosterone assay. To determine whether serum AMH would help in the diagnosis of intersex conditions, we assayed serum AMH levels in 107 patients with ambiguous genitalia of various etiologies. In XY patients, AMH was low when the intersex condition was caused by abnormal testicular determination (including pure and partial gonadal dysgenesis) but was normal or elevated in patients with impaired testosterone secretion, whereas serum testosterone was low in both groups. AMH was also elevated during the first year of life and at puberty in intersex states caused by androgen insensitivity. In 46,XX patients with a normal male phenotype or ambiguous genitalia, in whom the diagnosis of female pseudohermaphroditism had been excluded, serum AMH levels higher than 75 pmol/L were indicative of the presence of testicular tissue and correlated with the mass of functional testicular parenchyma. In conclusion, serum AMH determination is a powerful tool to assess Sertoli cell function in children with intersex states, and it helps to distinguish between defects of male sexual differentiation caused by abnormal testicular determination and those resulting from isolated impairment of testosterone secretion or action.

[Vitamin D status in the adolescent: seasonal variations and effects of winter supplementation with vitamin D3]

BACKGROUND

Recently, 25 hydroxyvitamin D (25 OHD) blood concentrations measured in adolescents during or at the end of winter were found very low. A concomitant stimulation of parathyroid function was observed. The aim of the present study was to test the biological effects of a treatment with vitamin D3 during winter.

POPULATIONS AND METHODS

The effects of vitamin D3 supplementation (100,000 IU, twice, at the end of November and of January) were assessed in 24 male Caucasian adolescents (mean age +/- SD: 14 y 6 m +/- 9 m). They were pupils in a lad-jockeys training center located in the countryside near Chantilly (49 degrees northern latitude). Blood concentrations of 25 OHD, calcium and intact parathormone (PTH) were measured three times: before each oral intake of vitamin D3 and 2 months after the last intake (March). A group of 32 male adolescents (mean age +/- SD: 14 y 9 m +/- 6 m), pupils in the same center, receiving no vitamin D and sampled in November and in March, served as controls.

RESULTS

In March, mean concentrations of 25 OHD (8.36 +/- 2.73 micrograms/L) were very low in vitamin D-not supplemented adolescents since 34% had levels less than 6 micrograms/L. In March, PTH concentrations (40.5 +/- 12.2 ng/L) were significantly (P = 0.0001) higher than in November (28.8 +/- 9.9 ng/L). In boys receiving vitamin D3 25 OHD serum concentrations measured in January (17.5 +/- 3.2 micrograms/L) and in March (18.7 +/- 4.0 micrograms/L) remained at a level not very different from that measured in November (16.6 +/- 3.8 micrograms/L). During the same period, calcium and PTH concentrations (32.2 +/- 11.7 ng/L in November; 32.4 +/- 14.3 in January and 32.9 +/- 13.5 ng/L in March) remained at their basal level as well.

CONCLUSIONS

The observation that, after winter, a relatively large number of adolescents presented low concentrations of 25 OHD suggests that, during winter, usual dietary intakes and/or vitamin D stores are not sufficient to provide for their needs. Administration of two oral doses of 100,000 IU of vitamin D3 could maintain the vitamin D status at its initial level. The efficiency of such a prophylactic treatment is also assessed by its effect on parathyroid function.

[Basedow disease in children: clinical and evolutive aspects]

PATIENTS AND METHODS

The initial symptomatology and long-term effects of antithyroid drug treatment are reported in children aged 11.7 +/- 3.2 years (52 girls, 16 boys) with hyperthyroidism due to Graves' disease.

RESULTS

A family history of thyroid pathology was found in half of the cases: 7% (five out of 68) of our patients have had another autoimmune disorder associated with hyperthyroidism. The most frequent and permanent clinical symptoms at diagnosis were goiter and tachycardia. Antithyroid drug treatment was always proposed at first line and resulted in a rapid decrease in clinical and biological signs of hyperthyroidism. Subtotal thyroidectomy (n = 19) was mostly performed because of non-compliance or recurrence of hyperthyroidism after medical treatment withdrawal. Significant adverse reaction (leukoneutropenia) was observed in only one patient. Survival remission times analysis (remission being defined as clinical and biological euthyroidism for more than 1 year after antithyroid drug withdrawal) realised in 50 subjects followed up for at least 2.5 years showed complete remission in 55% of the patients treated exclusively medically (n = 27), when lost to follow-up or surgically treated subjects were considered as incomplete observations. On the whole studied population (n = 50), the remission rate was of 30% (n = 15) with an average follow-up period after medical therapy withdrawal of 5.2 +/- 3.0 years (range: 1.4-12.3 years). At present, ten out of 15 can be considered as healed (remission time for at least 2.5 years). Moreover, according to survival analysis, 75% of the remissions have a probability to occur in a delay of 4.6 +/- 1.0 years after the beginning of medical treatment.

CONCLUSION

In this population, no remission after 7 years of antithyroid drug therapy was observed. Remission predictive factors remain to be defined.

Assessment of Turner's syndrome by molecular analysis of the X chromosome in growth-retarded girls

Turner's syndrome (TS) is a common disorder (1/2500 to 1/5000 female births) which is diagnosed at birth in approximately 20% of patients and during childhood or at puberty for the rest. Growth retardation is the most frequent clinical feature of TS, so we systematically searched for TS in female patients referred to our center because of short stature. Three hundred seventy-five female patients, 1 month to 18 yr old (mean +/- SD = 9(7/12) +/- 3(9/12), with growth retardation (less than -2 SD) and/or decreased height velocity were included in the study. Mean growth retardation was -2.57 SD +/- 0.79 (range: -1 to -7). Thirty-two percent of the patients had reached puberty. GH provocative tests were performed in 329 patients (87.7%), and 36 of these patients (11%) had impaired GH secretion (5 complete and 31 partial GH deficiency). TS was evaluated by Southern blot analysis of leukocyte DNA using a multiallelic polymorphic X chromosome marker (88% heterozygosity rate). Y chromosome PCR analysis was carried out if a pattern indicative of TS was obtained. Leukocyte DNA analysis produced an abnormal restriction pattern for 20 of the 375 cases (5.3%). There was a single hybridizing band in 13 cases, an allelic disproportion indicative of mosaicism in 6 cases, and 3 hybridizing bands in 1 case. One patient tested positive in the Y chromosome PCR analysis. Cytogenetic analysis showed 47 XXX trisomy in the patient with a 3-hybridizing-band pattern and confirmed the diagnosis of TS for 17 of the 19 suspected cases: 45 X: n = 7; 45 X/46 Xi(Xq): n = 4; 45 X/46 XX: n = 2; 46 Xi(Xq): n = 1; 45 X/46 Xr(X): n = 1; 45 X/46 XX/47 XXX: n = 1; 45 X/46 XY: n = 1. Cytogenetic analysis was normal (46 XX) for the 2 other patients. The TS phenotype is variable: dysmorphism is often missing or mild (particularly in cases of mosaicism), but growth is reduced in virtually all patients. Screening of 375 growth-retarded girls identified 18 cases of TS, of which 17 were diagnosed by molecular analysis. This incidence (4.8%) was significantly higher than the expected incidence in this population (0.8-1.6%: P < 0.001).

A mutation in the human leptin receptor gene causes obesity and pituitary dysfunction

The adipocyte-specific hormone leptin, the product of the obese (ob) gene, regulates adipose-tissue mass through hypothalamic effects on satiety and energy expenditure. Leptin acts through the leptin receptor, a single-transmembrane-domain receptor of the cytokine-receptor family. In rodents, homozygous mutations in genes encoding leptin or the leptin receptor cause early-onset morbid obesity, hyperphagia and reduced energy expenditure. These rodents also show hypercortisolaemia, alterations in glucose homeostasis, dyslipidaemia, and infertility due to hypogonadotropic hypogonadisms. In humans, leptin deficiency due to a mutation in the leptin gene is associated with early-onset obesity. Here we describe a homozygous mutation in the human leptin receptor gene that results in a truncated leptin receptor lacking both the transmembrane and the intracellular domains. In addition to their early-onset morbid obesity, patients homozygous for this mutation have no pubertal development and their secretion of growth hormone and thyrotropin is reduced. These results indicate that leptin is an important physiological regulator of several endocrine functions in humans.

Severe hyponatraemia after plastic surgery in a girl with cleft palate, medial facial hypoplasia and growth retardation

A ten-year-old girl with middle face hypoplasia, cleft lip and palate developed severe hyponatraemia on the first day following surgery. Final diagnosis was inappropriate secretion of antidiuretic hormone (ADH) and complete hormonal investigation revealed partial deficit in growth hormone secretion. The incidence of hormonal deficiency associated to midline facial malformations is discussed.

The Beckwith-Wiedemann syndrome phenotype and the risk of cancer

Beckwith-Wiedemann syndrome (BWS) comprises of a number of childhood abnormalities, often associated with one or more tumors. Thirty-eight patients were investigated to determine clinical and/or biological signs associated with a tumor presence. Our patients exhibited a higher incidence of tumor development (21%) than that previously reported, underlying the care with which such patients should be followed, when particular clinical features are observed: visceromegaly affecting three organs (liver, kidney, spleen), and also family history with sign of BWS such as macroglossia, omphalocele, hemihypertrophy, embryonic tumor), high body weight at birth (> or = +2 standard deviations and diastasis recti.

[Turner syndrome: spontaneous growth of stature, weight increase and accelerated bone maturation]

BACKGROUND

Since growth hormone is effective in increasing the height of girls with Turner's syndrome, it is important to dispose of growth and bone maturation curves in a large number of untreated patients.

POPULATION AND METHODS

Data on growth and bone maturation were collected from 160 patients with Turner's syndrome (50 have reached final height), born 1965-1991, untreated with growth hormone or anabolic steroids. X monosomy was found in half of the patients, mosaicism or X abnormality was present in the other half. Spontaneous puberty occurred in 25% (n = 25) of patients older than 13 years, 38 patients received estrogen after 13 years. Final heights were compared to predicted height according to Lyon's method.

RESULTS

Forty-five percent of patients were small for date. Height velocity decreased from 2 years of age and decreased faster during adolescence, when gonadal dysgenesis occurred. Bone maturation velocity decreased also during adolescence. Excessive weight appeared after the age of 5 years. Patients with partial deletion of the long arm of X (n = 6) were taller than the other girls (n = 44) (mean +/- DS) 152.5 +/- 3.1 cm, range 150-158 cm versus 142.5 +/- 4.9 cm, 130-150 cm (P < 0.0001). Final height was not modified by spontaneous puberty. Final height was correlated with birth weight (r = 0.7), maternal height (r = 0.5) and mid parental height (r = 0.5). Finally, the Lyon's method for predicted final height seemed to be suitable for this population, (r = 0.8, P < 0.001).

CONCLUSION

Appropriate growth curve is an essential clinical tool in evaluating treatment aimed at increasing final stature in patients with Turner's syndrome.

Vitamin D-dependent seasonal variation of PTH in growing male adolescents

Twenty-eight young male adolescents (age from 13 years 6 months to 15 years 9 months) from a horseback-riding school were studied. They were studied at the end of summer (September of 1993) and, six months later, at the end of winter (March of 1994). At each timepoint their height and weight were measured and their pubertal status determined. Blood was collected and 25-hydroxyvitamin D [25(OH)D], intact parathyroid hormone (PTH1-84), and 1,25-dihydroxy-vitamin D [1,25(OH)2D] were measured. After winter, weight and height had increased by a mean of 2.9 +/- 1.3 kg and of 3.3 +/- 1.2 cm, respectively. 25(OH)D concentrations which were 29.96 +/- 7.46 micrograms/L in September had significantly (p = 0.0001) fallen by a mean of 23.31 +/- 6.6 micrograms/L in March (6.61 +/- 2.04 micrograms/L). March and September concentrations of 25(OH)D were significantly correlated (r = 0.536, p = 0.0039). March values were negatively correlated with the pubertal status (r = 0.41; p = 0.03). In the meantime, PTH had significantly (p = 0.0001) increased by a mean of 8.59 +/- 8.53 ng/L (22.8 +/- 7.44 ng/L in September vs. 30.33 +/- 8.05 ng/L in March). A statistically significant correlation between PTH and 25(OH)D concentrations (r = 0.493; p = 0.0001) was obtained. Serum 1,25(OH)2D concentrations measured in September (37.7 +/- 12.94 ng/L) and in March (38.2 +/- 7.8 ng/L) were not different. March values were positively correlated with pubertal status (r = 0.49; p = 0.008). Modulation of PTH secretion by vitamin D appears to be a physiological mechanism occurring during adolescence. In spite of a marked depletion of vitamin D stores after winter, PTH values remained within normal range. Nevertheless, we cannot exclude that a more prolonged vitamin D deficiency could adversely affect bone metabolism during this critical period of life characterized by an increased need of vitamin D.

[Severe hyponatremia associated with anorexia nervosa: role of inappropriate antidiuretic hormone secretion?]

BACKGROUND

Anorexia nervosa may be revealed by hyponatremia or associated with it. This hyponatremia can be due to diuretics or laxatives abuse, potomania or inappropriate secretion of antidiuretic hormone as in the case reported here.

CASE REPORT

A 15 year-old girl was admitted for anorexia nervosa. She had secondary amenorrhea and asthenia and had lost 14 kg during the preceding 4 months. Her natremia ranged from 112 to 130 mEq/l with normal urinary sodium excretion, serum hypoosmolality (252 mosm/kg) and inappropriately elevated urinary osmolality (698 mosm/kg). Renal, adrenal and thyroid functions were normal. After water loading, patient remained euvolemic, with a negative free water clearance and an increased plasma ADH level with concomitant hyposmolality. A diagnosis of inappropriate secretion of antidiuretic hormone was made, after excluding other conditions such as potomania, drug abuse, vomiting, tumor and chronic lung disease.

CONCLUSIONS

Hyponatremia sometimes seen in anorexia nervosa must lead to the search of inappropriate antidiuretic hormone secretion.

Final height in Turner syndrome patients treated with growth hormone

The first treatment trials on patients presenting with Turner syndrome were successful in accelerating growth velocity. It is therefore essential to know the final height of the patients who were treated in order to ascertain whether or not growth hormone treatment increases final height. We are reporting on a group of 117 patients with Turner syndrome whose growth hormone treatment was initiated in 1986. The mean growth hormone dose was 0.74 IU/kg/week for an average period of 4 years. At the start of treatment, the patients' chronological age was 129/12 years, height -3.8 +/- 1.0 standard deviation scores (SDS) and bone age 10.5 +/- 2.1 years. Mean final height was 147.7 +/- 5.6 cm, i.e. a gain of 1.5 SDS. We noted no significant difference due to the type of chromosomal abnormality, nor to oxandrolone or estrogen-associated treatment. A significant correlation was found between final height, mean parental height, the duration of the treatment, height SDS at the start of treatment and growth hormone peak during pharmacological stimulation tests. However, there was no correlation between growth hormone dosage, chronological age and bone age at the start of treatment. These results show that the growth hormone treatment improves the final heights of patients with Turner syndrome.

A point mutation in the second zinc finger of the DNA-binding domain of the androgen receptor gene causes complete androgen insensitivity in two siblings with receptor-positive androgen resistance

We have analyzed the nucleotide sequence of complementary and genomic DNAs of the human androgen receptor (AR) gene in two siblings (patients 9006 and 9030) with receptor-positive complete androgen insensitivity (Rec(+)-CAI). Northern analysis indicated that mRNA of the AR was normal in size. However, its expression was relatively reduced in both patients. Consistent with the normal androgen-binding capacity (496 and 552 fmol/mg DNA for patients 9006 and 9030, respectively) but decreased DNA-binding ability (168 fmol/mg DNA) measured in genital skin fibroblasts, no mutation was found in both N-terminal and ligand-binding domains of the AR. However, a single base substitution (G-->A) was found in the second zinc finger of the DNA-binding domain at nucleotide 2372 of the AR cDNA in both cases. This resulted in the replacement of a highly conserved arginine residue (amino acid 614) by a histidine. When the mutated receptor plasmid was cotransfected into PC-3 cells together with the reporter chloramphenicol acetyltransferase gene, chloramphenicol acetyltransferase activity was not induced by 5 alpha-dihydrotestosterone treatment, confirming that the mutation renders the AR nonfunctional and can, therefore, be held responsible for the clinical features in these patients. These results highlight the importance of Arginine-614 in the second zinc finger of the DNA-binding domain of the AR in the protein-DNA interaction.

Parental allele specific methylation of the human insulin-like growth factor II gene and Beckwith-Wiedemann syndrome

In an attempt to elucidate the role of methylation in parental imprinting at the IGF-II gene locus, for which imprinting has already been described in the mouse, we undertook an allele specific methylation study of the human IGF-II gene (mapped to 11p15.5) in a control population and in patients with Beckwith-Wiedemann syndrome. In control leucocyte DNA (16 unrelated adults and eight families), the maternal allele of the IGF-II gene was specifically hypomethylated, whereas no such allele specific methylation was found for either the insulin or the calcitonin genes which are located in 11p15.5 and 11p15.1, respectively. Furthermore, the IGF-II gene specific hypomethylation was localised on the 5' portion of exon 9. In the patients with Beckwith-Wiedemann syndrome in which the IGF-II gene is thought to be involved and where paternal isodisomy has been described, hypomethylation of the maternal allele was conserved in leucocyte DNA, but abnormal methylation was detected in malformed tissues where the paternal allele was also demethylated. Some specific mechanism linked to methylation therefore seems to be involved in the pathogenesis of Beckwith-Wiedemann syndrome.

Molecular diagnosis of Turner's syndrome

Turner's syndrome is a common disorder which occurs in around 1/3000 live births in girls. Diagnostic use of polymorphic DNA markers for the X chromosome could help to reduce the number of time consuming karyotype analyses needed. The M27 beta probe maps on the X chromosome to Xcen-Xp11-22 and in 83% of female subjects detects heterozygosity with multiallelic polymorphism. In Southern blotting, a single X chromosome yields a single hybridisation band. In this study, genomic DNA was extracted from leucocytes of 49 patients with Turner's syndrome (karyotypes: 45,XO, n = 29; 45,XO/46,XX, n = 4; 46,Xi(Xq), n = 1; 45,XO/46,Xi(Xq), n = 4; 45,XO/46,Xr(X), n = 4; 45,XO/46,XY, n = 4; 46,XXp-, n = 3), digested with EcoRI or HindIII, and analysed by Southern blotting. The molecular data for each patient were compared with DNA controls (homozygous 46,XX, heterozygous 46,XX and 46,XY DNA). A single band of reduced intensity compared to homozygous 46,XX control DNA was seen in 41 cases. Two hybridisation bands of different intensities were seen in four patients, in one of whom mosaicism was suspected on the basis of molecular analysis, despite a 45,XO karyotype. In four cases, Turner's syndrome failed to be detected: one 45,XO/46,XX mosaicism with only 4% of 45,XO cells and three distal Xp deletions. DNA analysis appears to be a useful and rapid tool in screening for Turner's syndrome and could be an alternative to cytogenetic analysis in diagnosing the disorder when severe growth retardation or delayed puberty are not accompanied by a Turner phenotype.

Insulin-like growth factor-I gene analysis in subjects with constitutionally variant stature

The IGF-I gene from leukocyte DNA of a control population of normal stature was studied using Southern blotting. Restriction fragment lengths for 21 enzymes were determined and three restriction fragment length polymorphisms (RFLP) were found (EcoRV, HindIII, and PvuII). In addition, the IGF-I gene of 64 constitutionally short subjects, five Pygmies, and 10 constitutionally tall subjects was analyzed. No IGF-I gene alterations were detectable by Southern blot in any of these conditions. Linkage analysis using genetic markers (RFLP) yielded results that were uninformative for five constitutionally short families investigated, owing to the limited number of RFLP and their low incidence (17% for the 5.2-kb HindIII, 5-kb PvuII RFLP alleles, and 13% for the 13-kb EcoRV RFLP allele). The EcoRV RFLP was found to map near Exon 1. The incidence of the 13-kb polymorphic allele with EcoRV proved to be lower (4%) in the group with constitutionally short stature than in controls. These results could suggest that modifications in the region of the IGF-I gene may be involved in constitutionally short subjects.

[True hermaphroditism in a child with a chimeric XX/XY chromosome, a double erythrocyte population and an unusual Lewis (a+ b+) phenotype]

A 2 years-old Korean girl is seen because of ambiguous external genitalia. Surgical exploration shows the right gonad to be an ovary and the left one to be an ovotestis, thus demonstrating a true hermaphroditism. Cytogenetic studies of peripheral lymphocytes reveal a mixture of 46,XX and 46,XY cells, with a predominant XX cell line. The patient's red cells are composed of two distinct populations differing in three genetically independent blood group systems. The ratios of the two cell lines in various tissues, especially among the cells secreting Lewis antigens, appear to be very different and suggest several hypothesis to explain the highly unusual red cell Lewis phenotype Le (a+ b+). We conclude to a dispermic chimera, however the adopted status of this child prevents any identification of the maternal or paternal contributions. Because of the physical aspect it was decided to remove the ovotestis, to repair the external genitalia and to bring up this child as a female.

[Hydrocholecystis, unrecognized cause of painful abdominal crises in patients with sickle cell anemia]

The first case of painful abdominal crisis caused by hydrops of the gallbladder during sickle cell disease is reported. The cholecystosonography allowed diagnosis and supervision in a 4 year-old black boy with sickle cell anemia. The persistence of hydrops led to cholecystectomy. Pathophysiology is discussed according to the other etiologies reported in the literature.

Ultrasound examination of pubertal girls and of patients with gonadal dysgenesis

Girls with hypogonadism caused by hypothalamic lesions or chromosomal abnormalities need accurate pelvic exams to delinate pelvic structures. This work presents an evaluation of the usefulness of ultrasound examination of the pelvis in females with aberrant sexual development. Girls with these problems often need multiple pelvic examinations to monitor their uterine response to hormone therapy. Thirty-two patients with a variety of abnormalities including Mullerian agenesis and hypothalamic hypogonadism as well as patients with abnormal karyotype commonly associated with gonadal dysgenesis and male pseudohermaphrodism were studied. Repeat ultrasound scans were performed to quantitate uterine response to therapy. Ovarian visualization was usually possible, even in prepuberal girls. Following some patients at risk for gonadal tumors may be possible using repeat ultrasound examinations. The cooperation of the patients as well as of their families was gratifying, and the girls appeared to be more relaxed during ultrasound examination than during a pelvic examination.