Hypogonadotrophic hypogonadism associated with prelingual deafness due to a connexin 26 gene mutation.

In Mediterranean countries, almost half the incidence of non-syndromic congenital hearing loss is caused by mutations in the gap junction (GJ) connexin 26 gene (GJB2/DFNB1 locus). In this form of deafness the cochlear defect is usually isolated. We describe here the first case of hypogonadotrophic hypogonadism in association with this particular cochlear defect. The male patient had moderate deafness inherited from his deaf parents. All family members had a homozygous 35delG mutation in the connexin 26 gene. This mutation accounts for 70% of all connexin 26 gene mutations. The patient was referred to a paediatric endocrinology unit at 11 years of age for moderate growth retardation. Growth rate was normal until 11 years. The patient then presented delayed puberty (testicular volume 4 ml, penis length 4 cm) and did not undergo the usual pubertal growth spurt. LH and FSH secretory responses to GnRH at the age of 14.5 years (bone age 13.5 years), were: LH baseline level 1.1 IU/l, peak 34 IU/l; FSH baseline level 1.8 IU/l, peak 5.7 IU/l. Testosterone concentration was <0.11 ng/ml. From 11 to 14 years old, testosterone concentration ranged from 0.11 to 0.2 ng/ml. Anti-Mullerian hormone (AMH) level was 38.6 ng/ml (normal for Tanner stage I), cortisol 109 ng/ml, and ACTH 37 pg/ml., Karyotype was 46 XY. On MRI analysis, the anterior pituitary and olfactory bulbs were normal. These data were consistent with partial hypogonadotrophic hypogonadism of hypothalamic origin, and the patient was treated with testosterone. This report supports the possible involvement of connexins in puberty initiation. Connexins may play a part in the co-ordination and synchronisation of GnRH release.

Genetic, biochemical, and clinical studies of patients with A328V or R213C mutations in 11betaHSD2 causing apparent mineralocorticoid excess.

Apparent mineralocorticoid excess is a recessively inherited hypertensive syndrome caused by mutations in the 11beta-hydroxysteroid dehydrogenase type 2 gene, which encodes the enzyme normally responsible for converting cortisol to inactive cortisone. Failure to convert cortisol to cortisone in mineralocorticoid-sensitive tissues permits cortisol to bind to and activate mineralocorticoid receptors, causing hypervolemic hypertension. Typically, these patients have increased ratios of cortisol to cortisone and of 5alpha- to 5beta-cortisol metabolites in serum and urine. We have studied 3 patients in 2 families with severe, apparent mineralocorticoid excess and other family members in terms of their genetic, biochemical, and clinical parameters, as well as normal controls. Two brothers were homozygous for an A328V mutation and the third patient was homozygous for an R213C mutation in the 11beta-hydroxysteroid dehydrogenase type 2 gene; both mutations caused a marked reduction in the activity of the encoded enzymes in transfection assays. The steroid profiles of the 7 heterozygotes and 2 other family members studied were completely normal. The results of a novel assay used to distinguish 5alpha- and 5beta-tetrahydrometabolites suggest that 5beta-reductase activity is reduced or inhibited in apparent mineralocorticoid excess. In 1 patient undergoing renal dialysis for chronic renal insufficiency, direct control of salt and water balance completely corrected the hypertension, emphasizing the importance of mineralocorticoid action in this syndrome.

The cortisol-cortisone shuttle in children born with intrauterine growth retardation.

We evaluated the involvement of a possible dysfunction of 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) in the fetal growth retardation and poor growth rates of children born with intrauterine growth retardation (IUGR). Children with IUGR have a nephron deficit and are also at risk of developing cardiovascular diseases, high blood pressure, glucose intolerance, and dyslipidemia later in life. The major site of 11beta-HSD2 production is the kidney and its deficit causes hypertension. We investigated plasma concentrations of cortisol (F) and cortisone (E) and the F/E ratio in 26 control children and in 40 IUGR children without catch-up growth. We also determined cholesterol, HbA1C, insulin, and glucose levels in plasma. Mean F values were 106 +/- 54.2 ng/mL in control children and 114.6 +/- 53.2 ng/mL in IUGR children. Mean E values were 19.5 +/- 7.1 ng/mL in control children and 17.9 +/- 6.85 ng/mL in IUGR children. The mean F/E ratio for control children was 5.5 +/- 1.7. Eight (20%) of the IUGR children (IUGR children of group 1) had high F/E ratios more than 2 SD above the normal mean: 13.15 +/- 4.26, (p < 0.0001) as compared to control children, whereas the other 32 children (IUGR children of group 2) had normal F/E ratios: 5.40 +/- 1.43 (p = 0.68). Childhood height was significantly lower for group 1 than group 2 children (-3.63 SD and -2.92 SD, respectively: p < 0.01) and was negatively correlated with the F/E ratio (p < 0.01). Systolic blood pressure was higher for group 1 (p = 0.005) and for group 2 (p = 0.015) than for control children. The diastolic pressure in IUGR children of group 1 was higher than that in control children (p = 0.013) and slightly higher than that in group 2 (p = 0.1, ns). Cholesterol concentrations were higher in group 1 than in group 2 (p = 0.029), and controls (p = 0.017) and correlated positively with F/E (0.02 < p < 0.05). Fasting insulin concentrations were higher in group 1 than in group 2 (ns) and controls (ns). There was no difference in mean fasting glucose concentrations, or HbA1C between the three groups. Twenty percent of our children with IUGR and poor growth rates had high F/E ratios, suggesting a possible partial 11beta-HSD2 deficit. Whether these children are at high risk of developing cardiovascular diseases as adults remains to be further evaluated.

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.

Radioimmunoassay of cortisone in serum, urine, and saliva to assess the status of the cortisol-cortisone shuttle.

We have developed a new assay for cortisone (E) in serum, saliva, and urine involving Celite chromatography followed by RIA with 125I-labeled E and scintillation proximity assay. The chromatography step separates cortisol (F) from E, and in combination with their RIAs, permits assessment of the status of the F-E shuttle. We report the results of basal, postcorticotropin (ACTH), and postdexamethasone E and F concentrations and their circadian fluctuations in the serum, saliva, and urine of healthy volunteers. The serum and urine F/E ratios were increased in patients with ectopic ACTH secretion, whereas in adrenal adenoma and Cushing disease only the urinary ratio was increased. In chronic renal insufficiency this ratio was increased in serum (23.5 +/- 3.9) but diminished in saliva (0.38 +/- 0.11), and in apparent mineralocorticoid excess the ratios were high in serum (44.3 +/- 9.3) and urine (5.35 +/- 0.85) compared with those of healthy subjects (serum 9.8 +/- 3.5, urine 0.52 +/- 0.29, saliva 0.52 +/- 0.29).

Major circadian variations of glucose homeostasis in a patient with Rabson-Mendenhall syndrome and primary insulin resistance due to a mutation (Cys284-->Tyr) in the insulin receptor alpha-subunit.

We have performed clinical, in vitro biochemical, and genetic studies of a patient with severe insulin resistance, considerable growth restriction, and Rabson-Mendenhall syndrome (patient RM-3). The blood IGF-I level was undetectable in this patient, although the GH level was moderately decreased. During the postprandial period, glycemia, ketonuria, and plasma glucagon were very elevated despite high doses of exogenous insulin (glucose levels up to 30 mmol/L). In the postabsorptive state, blood glucose was normalized with small amounts of insulin; ketonuria, and glucagon levels were reduced but remained supranormal. Erythrocytes and cultured skin fibroblasts from the patient displayed a decrease in cell surface insulin receptors (IRs). The ability of physiologic concentrations of insulin to stimulate metabolic processes was altered in patient fibroblasts. Analysis of the IR gene by denaturing gradient gel electrophoresis and direct sequencing showed a homozygous missense mutation in exon 3, replacing Cys284 by Tyr in the alpha-subunit. In conclusion, marked primary insulin resistance was evidenced in patient cells as a result of a structural alteration in the IR alpha-subunit. The in vitro studies could not account alone for the in vivo metabolic alterations because glucose homeostasis varied considerably during the day in the patient.

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.

Growth retardation in constitutionally short children is related both to low serum levels of insulin-like growth factor-I and to its reduced bioavailability.

Measurements of serum levels of insulin-like growth factor (IGF)-I, IGF-II and IGF binding protein (IGFBP)-1 have been carried out in conjunction with Western ligand blot analysis of serum IGFBPs in 39 constitutionally short children and adolescents and compared with those of 27 age-matched normal subjects (and also with 23 hypopituitary patients). Estimated amounts of the two forms of IGFBP-3 (42 and 39 kDa) and of IGFBP-2 (34 kDa) were obtained by laser densitometry scanning. Mean serum levels of IGF-I were decreased by 46% +/- 5% in short, compared to normal, prepubertal children (P < 0.01) and reduced slightly, but not significantly, in short pubertal children. IGFBP-1 levels decreased with age in short children, as they did in normals, but average values were significantly higher in short children (P < 0.001). There was also a tendency for higher IGFBP-2 levels in short prepubertal and pubertal children. IGFBP-3 bands were of equal intensity in short and normal subjects. Physiologically, IGFBP-3 undergoes limited proteolysis which results in facilitated dissociation of the IGFs, particularly IGF-I, and an increase in their turnover. Western immunoblotting detects proteolytic fragments of IGFBP-3 (the major one being of 30 kDa) that are not detected by ligand blotting. The ratio of proteolysed to total IGFBP-3 in short prepubertal children (36.8% +/- 2.6%) was significantly lower (P < 0.01) than in normal prepubertal subjects (60.6% +/- 8.9%). This lesser proteolysis of IGFBP-3 would explain the excessive levels of IGFBP-3 (detected by ligand blotting) relative to IGF levels in short children. These results suggest that growth retardation in short children involves IGF-I deficiency resulting from both decreased IGF-I synthesis and lesser bioavailability of the circulating IGF-I bound to IGFBP-3. High IGFBP-1 levels may also contribute towards limiting the availability of IGF-I to its target cells.

11 beta-Hydroxysteroid dehydrogenase deficit: a rare cause of arterial Hypertension. Diagnosis and therapeutic approach in two young brothers.

We report the clinical history and results of endocrine investigations in two brothers born to consanguineous parents, who presented with hypokalemia and arterial hypertension when they were aged 2 and 6 years. The hormonal serum assay results, including extremely low values for aldosterone and plasma renin activity, favored the existence of apparent mineralocorticoid excess. A diagnosis of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) deficiency was made, based on assays of the hydrogenated urinary metabolites of cortisol and cortisone, as well as of corticosterone and dehydrocorticosterone. Indeed we found a very low rate of urinary elimination of cortisone metabolites: tetrahydrogenated cortisone was reduced to between 0.10 and 30 mumol/24 h, which is 15-100 times lower than the normal rate; hexahydrogenated cortolones alpha and beta were found to be 7- to 20-fold lower than normal levels; and the 11-keto-17-ketosteroid derivatives of cortisone were also reduced. Urinary elimination of the cortisol-reduced metabolites 5 beta- and 5 alpha-tetrahydrogenated cortisol were slightly reduced or normal. These results argue in favor of a deficit in the enzyme 11 beta-HSD, which oxidizes cortisol into cortisone. A moderate defect in the conversion of cortisol into 5 beta-THF compared to normal conversion into 5 alpha-THF was also found. With respect to corticosterone metabolism, we demonstrated the presence of a defect in the oxidation of that steroid into dehydrocorticosterone, also due to the deficit in 11 beta-HSD. Arterial hypertension and hypokalemia were corrected by treatment with dexamethasone, concomitantly with correction of the low aldosterone and plasma renin activity levels. On the other hand, during this treatment, urinary concentrations of the metabolites of cortisol, cortisone and corticosterone were only moderately affected.

[Turner syndrome: spontaneous growth of stature, weight increase and accelerated bone maturation]. / Syndrome de Turner: croissance staturopondérale et maturation osseuse spontanées.

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.

Plasma neurotensin levels in humans: relation to hormone levels in diseases involving the hypothalamo-pituitary-thyroid axis.

This study was aimed to investigate, in humans, the possible relationship between plasma neurotensin (NT) levels and the activity of the hypothalamo-pituitary-thyroid axis. Neurotensin was measured by radioimmunoassay in 14 healthy adult volunteers and in 41 patients among whom 10 were considered as controls and 31 had thyroid dysfunction according to free thyroxine and thyrotropin plasma values. Basal NT levels were not significantly different in healthy adults and in control patients: 9.7 +/- 1.1 fmol/ml (mean +/- SEM) vs 13.3 +/- 2.9 fmol/ml, respectively. In patients with central hypothyroidism the NT level was significantly lower (5.7 +/- 1.2 vs healthy volunteers and controls; p < 0.05) and in patients with peripheral hypothyroidism and hyperthyroidism the NT level was significantly higher (35.9 +/- 12.8 and 29.9 +/- 9.5 fmol/ml, respectively, vs healthy adults (p < 0.01) and vs controls (p < 0.05)). After thyrotropin-releasing hormone (TRH) injection (250 micrograms iv) in nine subjects (two control patients, five patients with hypothyroidism and two patients with hyperthyroidism), NT levels decreased independently of the endocrine status from mean values of 13.4 +/- 8.4 at basal level to 7.3 +/- 0.8 fmol/ml 30 min after injection (p < 0.01 on paired percentage decrease values). These data suggest that plasma NT levels in humans depend upon the pituitary-thyroid status and indicate that TRH could exert a negative regulation on circulating NT levels.

Nutritional status and growth hormone-binding protein.

To study the effects of nutrition on growth hormone (GH) receptor status, the plasma GH-binding protein was evaluated under conditions of poor nutrition, anorexia nervosa, celiac disease, and obesity. Nine patients, aged 12-30 years, presented anorexia nervosa and had a mean weight loss of -19% of their initial weight at the time of the study. Ten patients with celiac disease, aged 3-14 years, had a mean height at -4.2 SD, and normal body weight for height. Fourteen severely obese children, aged 3-10 years, had a mean body mass index (BMI) of 25.7 +/- 0.9. GH-binding protein was low in patients with anorexia nervosa (16.8 +/- 1.9% of radioactivity) and in patients with celiac disease (16.1 +/- 2.2%) whereas it was very high in obese children (57.2 +/- 3.3%). A strong correlation was found between GH-binding protein and BMI. GH-binding protein was also correlated with insulin-like growth factor-1 plasma levels. Nutrition is an important regulator of the GH receptor/binding protein. The growth failure presented by undernourished children is associated with partial GH resistance and low GH receptor level. On the contrary, children with obesity and normal growth have a high GH receptor level.

IGFs and their binding proteins.

Insulin-like growth factors (IGFs), initially known as somatomedins, and their specific, high-affinity binding proteins (IGFBPs) are synthesized in most tissues, but principally in the liver. The interest of measuring their circulating levels, which reflect liver production, is to obtain indications as to their endocrine function and regulation. IGF-I plays a pivotal role in post-natal growth. Its half-life is significantly increased by its association with IGFBPs and its serum levels reflect somatotropic status, unlike growth hormone (GH) which has a much shorter half-life and whose secretion comes in pulses. Since investigation of growth retardation must include the most finely tuned appreciation possible of somatotropic secretion, assays of IFG-I and electrophoretic analysis of IGFBP profile can be useful tools, both diagnostically and therapeutically, and can help in determining the need or otherwise for GH treatment, especially in view of the growing demand for such therapy.

The application of a new highly-sensitive radioimmunoassay for plasma 21-deoxycortisol to the detection of steroid-21-hydroxylase deficiency.

21-deoxycortisol (21-DF) is a steroid of strictly adrenal origin formed by the 11-hydroxylation of 17-hydroxyprogesterone. This metabolic pathway is minor in normal subjects, in whom basal plasma concentrations range from 0.03 to 0.63 nmol/L and from 0.865 to 1.50 nmol/L after adrenocorticotrophic hormone (ACTH; Synacthène Immédiat, Ciba/Geigy, France). However, this metabolic pathway becomes major in 21-hydroxylase-deficient patients: in those who have the classical form of congenital adrenal hyperplasia (CAH) basal plasma 21-DF levels can attain more than 144 nmol/L. The synthesis of two isomers, E and Z, of the 21-deoxycortisol-3-carboxymethyloxime (CMO) hapten enabled us to prepare the corresponding E and Z immunogens by coupling them to bovine serum albumin (BSA), as well as the corresponding iodinated E and Z 21-DF-3-CMO-histamine tracers. We developed a very sensitive radioimmunoassay for 21-DF in plasma by associating an anti-21-DF-3-CMO-BSA-E isomer antibody to an iodinated 21-DF histamine-Z isomer (standard curve IC 50 = 8 pg/tube). This plasma 21-DF radioimmunoassay allowed diagnosis of the classical form of CAH in untreated newborn (basal 21-DF levels greater than 144 nmol/L), as well as the late-onset form (post-ACTH 21-DF levels greater than 11.54 nmol/L), and also permitted detection of 21-hydroxylase-deficient heterozygotes of both forms of CAH among the general population (post-ACTH 21-DF levels between 2.02 and 9.52 nmol/L).

Pharmacokinetics of recombinant human insulin-like growth factor I given subcutaneously to healthy volunteers and to patients with growth hormone receptor deficiency.

The pharmacokinetics of recombinant human insulin-like growth factor I (rhIGF-I) were studied in healthy volunteers and in patients with growth hormone receptor deficiency (GHRD; Laron syndrome). Following single subcutaneous injections of rhIGF-I, 40 and 80 micrograms/kg, to healthy volunteers, the peptide was absorbed slowly, with a maximum concentration reached after about 7 hours. Following daily multiple subcutaneous injections of rhIGF-I, 40 micrograms/kg, trough concentrations of IGF-I were increased by 277 +/- 50 micrograms/l (mean +/- SD) from baseline. IGF-I was thus characterized as a low-clearance peptide, with a clearance and half-life estimated at about 0.20 ml/minute/kg and 20 hours, respectively, in healthy volunteers. The volume of distribution was low, about 0.20-0.36 litres/kg, the bioavailability of subcutaneously administered rhIGF-I was 100%, and the rate of production of IGF-I was estimated to be about 50 micrograms/kg/day (3.5 mg/day). Patients with GHRD had low baseline IGF-I concentrations (30-50 micrograms/l) and a much more rapid turnover of IGF-I compared with that in healthy volunteers. The clearance and half-life of IGF-I were estimated to be about 0.60 ml/minute/kg and 6 hours, respectively. The volume of distribution was about the same as in healthy subjects. Due to the rapid turnover of IGF-I, trough IGF-I concentrations were increased to just above baseline during subcutaneous injections of 40 micrograms/kg once daily for 7 days. The maximum increase in IGF-I levels was 111 +/- 12 micrograms/l and 150 +/- 3 micrograms/l following daily subcutaneous injections of 40 x 1 and 40 x 2 micrograms/kg for 7 days, respectively.

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.

Effects of nutrient intake on growth, insulin-like growth factors, and their binding proteins in a Laron-type dwarf.

In Laron-type dwarfism, a basal growth rate independent of GH and insulin-like growth factor-I (IGF-I) is maintained. This represents a unique model to further assess the relationship between growth and nutritional status. In a child aged 3 yr, 7 months with severe anorexia, growth was followed in relation to his caloric intake. While receiving 496 Cal/day with 11.6 g/day protein, he grew at a rate of 2 cm/yr (period I). The mean plasma IGF-I level was below 0.07 U/mL, insulin was 3.8 +/- 0.2 microU/mL, and blood glucose was 2.9 +/- 0.3 mM/L. During moderate hyperalimentation with 1280 Cal/day and 38.3 g/day protein (period II) for 7 months, growth rate increased to 9 cm/yr with no significant change in plasma IGF-I and persistence of relative hypoinsulinemia (low response to oral glucose tolerance test). IGF-binding proteins, analyzed by Western ligand blotting, showed that 41.5- and 38.5-kilodalton forms, which were initially low, increased to form a pattern similar to that observed in hypopituitarism. These results suggest that catch-up growth did not require normal circulating GH and/or IGF-I activity. Therefore, nutrition contributes to catch-up growth and achievement of potential statural growth by a distinct cellular effect.

[Creutzfeldt-Jakob disease in 4 children treated with growth hormone]. / Maladie de Creutzfeldt-Jakob chez quatre enfants traités par hormone de croissance.

Creutzfeldt-Jakob disease was diagnosed in four growth hormone recipients at the age of 10, 11, 18 and 19 years. To our knowledge, the two first cases are the first instances of Creutzfeldt-Jakob disease recorded in children. Three of them were still being treated with synthetic hormone at the onset of the disease. Neurological disorders: ataxia and diplopia, appeared first, dementia and myoclonus appeared later. Eighteen cases of Creutzfeldt-Jakob disease in growth hormone recipients are now recorded, and the present risk of Creutzfeldt-Jakob disease in pituitary growth recipients is estimated to be 1/300. Because of the long incubation period, new cases are to be feared. Other causes of iatrogenic Creutzfeldt-Jakob disease are reviewed. These facts incite to consider carefully using products of human origin in human therapy. The interactions between growth hormone, prion and host's genomic make-up are still not clear.