Hypoglycaemia and Russell-Silver syndrome

AIM

To determine both the incidence and aetiology of chronic hypoglycaemia in symptomatic children with Russell-Silver syndrome (RSS) during the first four years of life.

STUDY DESIGN

Twenty-four children with RSS under the age of 4 years, who had either clinical symptoms of hypoglycaemia or previous evidence of biochemically documented hypoglycaemia, were admitted to hospital for 48 hours to perform a 24-h cortisol/glucose profile and a diagnostic fast in those who did not develop spontaneous hypoglycaemia. A dietary assessment was also performed. Glucose profile was assessed in 20 children and cortisol profile in 16; combined glucose and cortisol profile in 15 children. Eight children had a diagnostic fast. Mean chronological age at time of assessment was 2.2 +/- 0.8 years (range 1.1-3.9 years).

RESULTS

Ten of 24 children had previously been documented as having hypoglycaemia. Seven of 12 patients were growth hormone (GH) insufficient after a glucagon test. Their feeding pattern was described as 'poor and picky eaters' in all, seven requiring nasogastric tube feeding. The mean spontaneous energy intake (n = 8) was 56 +/- 19.6 kcal/kg/day (range 38-90). Nocturnal sweating was the commonest symptom (23.96%), followed by irritability (11.46%), tantrums (7.29%), pallor and shakiness (3.13%). The glucose profile in seven children showed hypoglycaemia but only four were symptomatic. None of the children was cortisol deficient. The mean period of fasting was 11.8 +/- 4 hours (range 3-18 h). No metabolic/hormonal abnormality, with the exception of GH insufficiency, was detected at the time of hypoglycaemia.

CONCLUSION

Children with RSS are prone to develop spontaneous hypoglycaemia especially if they are not fed both frequently and regularly. The most likely explanation is accelerated starvation and/or GH insufficiency. We suggest guidelines to minimise hypoglycaemia in these children.

Efficacy and safety of Valtropin in the treatment of short stature in girls with Turner's syndrome

Valtropin (somatropin, BioPartners and LG Life Sciences [LGLS]) is a recombinant human growth hormone (GH) preparation produced using a yeast expression system. An open single-arm phase III study was conducted to evaluate efficacy and safety at a dose of 0.16 IU/kg/day (0.053 mg/kg/day) s.c. for 12 months in the treatment of short stature in girls (n = 30, aged 2-9 years) with Turner's syndrome. The primary efficacy variable was height velocity (HV) at 12 months. Secondary efficacy variables included serum GH dependent growth factors. HV increased from 3.8 +/- 1.8 cm/yr at baseline to 9.7 +/- 1.6 cm/yr (mean +/- SD) after 12 months of treatment. Marked treatment effects were also observed on other growth parameters, serum insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3). Treatment was well tolerated with no significant adverse events. It is concluded that Valtropin is as safe and effective as other human GH preparations for the treatment of growth failure in girls with Turner's syndrome.

Growth hormone secretion and long-term growth data in children with psychosocial short stature treated by different changes in environment

OBJECTIVES

We assessed auxological and endocrine data of 65 children (32 girls) from 51 families with an average age of 6.6 years (range, 0.9 to 16.5 years, all but five prepubertal) with psychosocial short stature.

METHODS

Fifty-one patients had an assessment of growth hormone (GH) secretion. Thirty-four were subjected to repeated testing with the first test being performed when the child was still in the adverse environment and the next testing after the child was removed. Twenty-five out of those 34 were repeatedly tested during one uninterrupted hospital admission with limited parental access. Thirty patients had a definite, long-term change in their environment (13 were separated from their families) and were assessed concerning their auxological data.

RESULTS

Of the 34 patients who had repeated endocrine testing, 11 (32%) showed reversible GH deficiency (GHD), nine (26%) increased their previously normal peak GH concentration, and six (18%) had apparently irreversible GHD. Patients who had a change in environment increased their mean height velocity SDS from -0.9 (SD 1.5) to +1.5 (2.3) (p < 0.0001). Accordingly, height SDS increased from -2.9 (SD 0.8) before to -2.6 (SD 0.8) after the change (p < 0.001).

CONCLUSION

One of the diagnostic features of psychosocial short stature is reversible GH insufficiency, which usually normalises after the child is separated from the adverse environment. Catch-up growth is always found after a positive change in the environment, and may occur within the family. However, if a change in environment is not possible, GH therapy may be an option.

Body mass index and hypothalamic morphology on MRI in children with congenital midline cerebral abnormalities

Obesity is common in children with congenital midline defects of the brain, due to various endocrine reasons: hypothyroidism, growth hormone deficiency and inappropriate cortisol replacement. However, obesity occurs more often in the absence of an endocrinopathy. We reviewed 31 patients (10 females, 21 males) with midline intracranial defects (holoprosencephaly, absence of septum pellucidum, absence of corpus callosum, optic nerve hypoplasia) and correlated the morphology of the hypothalamus with body mass index (BMI), as BMI SDS. Endocrinopathies were present in 16 out of the 31 patients. We conclude that there was a trend of increasing mean BMI SDS with increasing hypothalamic abnormality, although this was not statistically significant.

Final height in psychosocial short stature: is there complete catch-up?

AIM

To determine whether children with psychosocial short stature attain their genetic height potential.

METHODS

We report on 18 children (10 girls, 8 boys) diagnosed by a multidisciplinary team as having psychosocial short stature. All the children had had some kind of change in their environment (9 were separated from their families), and increased their mean height velocity standard deviation score (SDS) from -0.7 (1.3) to +3.6 (4.8) (p < 0.005) as well as their height SDS from -3.0 (0.3) to -2.6 (0.9) in the first year after the change. All the patients were postpubertal and had reached their near final height (mean age, 20.0 y; range, 16.0-23.3).

RESULTS

Only 3 out of 18 had a greater final height than the mid-parental target height, 14 out of 18 had a near final height within the mid-parental target range (95% tolerance limits of the mid-parental height (+/- 2 SD = +/- 10 cm). Nevertheless, mean final height expressed in height SDS for the whole group was significantly shorter with -2.4 SDS compared with the mean of the mid-parental target height of -1.5 SDS (p < 0.001). Surprisingly, initial catch-up growth did not correlate with final height attainment.

CONCLUSION

The majority of patients will attain a stature within the range of mid-parental target height, although towards the lower limit of this range.

Disorders of pubertal development

Puberty is the period of life during which reproductive capability is acquired. It is characterized clinically by the acquisition of secondary sexual characteristics associated with a growth spurt, and on average takes 3-4 years. Early maturation is defined as the development of sexual characteristics before the age of 8 years in girls and 9 years in boys. Delayed puberty is defined when there are no signs of puberty at the age of 13.4 years in girls and 14 years in boys (2 SD above the mean of chronological age for the onset of puberty). There are many forms of premature sexual maturation: gonadotrophin-dependent (central, or 'idiopathic' or 'true' precocious puberty) and gonadotrophin-independent precocious puberty (McCune-Albright syndrome in girls, testotoxicosis in boys); isolated premature thelarche (in the forms of classical, atypical and variant); premature adrenarche (characterized by the production of significant quantities of androgens between 5 and 8 years of age); premature menarche. The differential diagnosis of delayed puberty is between constitutional delay of growth and puberty, pubertal delay secondary to chronic disease and hypogonadotrophic hypogonadism.

Body composition in early onset eating disorders

BACKGROUND

Body mass index (BMI) or equivalent weight for height indices are the most widely used measures of body composition in early onset and adolescent eating disorders. Although of value as screening instruments the limitation in disease states is their inability to discriminate fat and fat-free components of body weight.

OBJECTIVE

To compare height-adjusted fat and fat-free components of body composition in children and young adolescents with different types of eating disorders with those of age matched reference children.

DESIGN

Weight, height, triceps and subscapular skinfold thickness were measured in 172 children (aged 7-16 y) with eating disorders receiving specialist treatment. Fat mass index (FMI) and fat-free mass index (FFMI) were calculated using Slaughter's and Deurenberg's equations and normalisation for height. Using data from 157 normal children, representative of the UK 1990 growth reference data, reference curves for FMI and FFMI+/-2 s.d. were derived. Results for patient groups were superimposed on these reference curves.

RESULTS

FMI and FFMI were both reduced in eating disorders associated with malnutrition, including anorexia nervosa (AN). AN subjects did not differ from other subjects with comparable degrees of malnutrition. Children with eating disorders of normal weight, such as bulimia nervosa and selective eating, did not differ significantly from reference children in their relative FM and FFM.

CONCLUSIONS

FM and FFM merit independent consideration in disorders of malnutrition in children, rather than expressing data as percentage body fat or percentage BMI. The implications of loss of FFM on growth and development merit further investigation.

Growth hormone treatment does not alter lower limb asymmetry in children with Russell-Silver syndrome

BACKGROUND

Growth hormone (GH) treatment has been proven to have a beneficial effect on growth in children with Russell-Silver syndrome (RSS).

METHODS

We describe 7 prepubertal children with RSS and lower limb asymmetry treated with GH for 3 years.

RESULTS

There was a significant increase in height without any significant change in the asymmetry.

CONCLUSIONS

We conclude that the rapid growth acceleration to GH treatment does not alter the lower limb asymmetry in children with RSS.

Management of hyponatraemia in patients with acute cerebral insults

Hyponatraemia is a common finding in patients with acute cerebral insults. The main differential diagnosis is between syndrome of inappropriate ADH secretion and cerebral salt wasting. Our aim is to review the topic of hyponatraemia in patients with acute cerebral insults and suggest a clinical approach to diagnosis and management.

Idiopathic short stature

Idiopathic short stature (ISS) is a term used to describe the status of children with short stature that cannot be attributed to a specific cause. Many children diagnosed as having ISS have partial GH insensitivity, which can result from disturbances at various points of the GH-IGF-I axis. Several clinical studies on spontaneous growth in ISS showed that adult height was almost in the range of target height. GH treatment led to adult height not significantly higher than the pretreatment predicted adult height in most reports. No metabolic side effects have been observed, even when the dose was higher than in GH deficiency. Manipulation of puberty with gonadotrophin releasing hormone analogues reported by a few authors in a small number of children has shown conflicting results. Long-term psychological benefits of GH therapy for short normal children have not been demonstrated to date.

Morbidity and mortality associated with vasopressin replacement therapy in children

OBJECTIVE

To assess the incidence and associated risk factors of adverse reactions of DDAVP treatment of children with diabetes insipidus, comparing different routes of administration.

DESIGN

We retrospectively studied 103 children (44 females, 59 males) with cranial diabetes insipidus (mean age 6.9 years at diagnosis) treated with intramuscular (59), intranasal (84) and/or oral (64) DDAVP, over a mean follow-up period of 5.2 years.

RESULTS

Eight patients died. For at least two children death was related to water intoxication. Major complications (symptomatic water overload with or without seizures) or asymptomatic hyponatraemia were observed in 33 patients. The incidence of total complications was significantly higher in cortisol deficient patients than in those with normal cortisol reserve (36% vs 6%). In patients on concomitant carbamazapine treatment major complications were more frequent in comparison to the remaining patients (33% vs 10%). Although not achieving significance, there were fewer complications using the oral route.

CONCLUSIONS

Caution is needed in managing patients with DI, especially if risk factors such as cortisol deficiency or concomitant carbamazepine treatment are present. The oral route of administration seems to be preferred for both convenience and safety. Major changes in dose and formulation should be undertaken in hospital.

Multiple pituitary hormone deficiency: management of puberty for optimal auxological results

The overview in this paper focuses on ways of achieving optimal auxological results in puberty, principally in idiopathic and congenital multiple pituitary hormone deficiency (MPHD), suggested by the co-authors. We agreed that diagnosing gonadotrophin insufficiency/deficiency is difficult in young children and should be repeated in late prepuberty, but a firm diagnosis of MPHD helps avoid endocrine re-testing at the end of growth. The hypothalamic-pituitary axis must be reassessed periodically in evolving endocrinopathies, though current practice varies widely. Optimum age to induce puberty is 11-12 years in girls and 13-14 boys, and sex steroids are the preferred agents. Short-course testosterone to increase micropenis size is advantageous, but inducing early testicular maturation is not known to improve later fertility. There is also little evidence for increasing the dose of GH during puberty, though therapy should continue to final height, and possibly until peak bone mass is achieved. Delaying puberty is an option in septo-optic dysplasia, and minimising the dose of hydrocortisone is crucial in treating ACTH/cortisol insufficiency. Many unresolved questions remain in this difficult area.

An open-label acceptability study of Norditropin SimpleXx--a new liquid growth hormone formulation

A new liquid formulation of hGH (Norditropin SimpleXx) has been developed to avoid the need for reconstitution before administration. In addition, the liquid GH formulation has been combined with an advanced pen delivery system, either with or without a needle auto-insertion mechanism. This study was designed to assess the acceptability of the new system compared with the patient's previous system. A total of 103 children with GH deficiency received a daily injection of Norditropin liquid GH for 12 weeks with a choice of a pen/auto-insertion system. Acceptability was determined by nurse-supervised questionnaires administered to the patients and parents. Following treatment, 94% of patients preferred the Norditropin liquid GH system. This preference was irrespective of the previous system in use, patient age or length of GH therapy. More patients found it the less painful system (50% vs 13%), 92% of patients found it more convenient, and the formulation was well tolerated. In conclusion, Norditropin liquid GH was very well accepted and preferred by the majority of patients. It avoided reconstitution which had been a major cause of dissatisfaction with the patients' previous systems, and resulted in greater convenience and reduced levels of pain associated with injection.

The anabolic steroid oxandrolone increases muscle mass in prepubertal boys with constitutional delay of growth

The aim of this study was to investigate the effect of oxandrolone on body composition in boys with constitutional delay of growth and puberty. In 14 prepubertal boys, height, weight, triceps and subscapular skinfolds and upper arm circumference were measured. Body mass index, the ratio of subscapular to triceps skinfolds and the upper muscle area were also determined. The difference of the various measurements and indices, 3 to 6 months before and after commencement of oxandrolone treatment, were calculated, while the boys remained prepubertal. We observed a marked increase in body mass index, a decrease of triceps and subscapular skinfolds, an increase in the ratio of subscapular to triceps skinfolds and also an increase in upper muscle area after the onset of oxandrolone treatment. These results suggest that low dose oxandrolone administration in prepubertal boys with constitutional growth delay causes a disproportionate increase of weight to height which is largely due to increased body muscle.

Growth hormone and segmental growth in survivors of head and neck embryonal rhabdomyosarcoma

AIMS

To assess the impact of treatment for embryonal rhabdomyosarcoma on spinal growth and limb length and examine the response of these parameters to growth hormone (GH) treatment.

METHODS

We conducted a retrospective case note review of 17 survivors of head and neck rhabdomyosarcoma followed up at a single institution. All children had been treated with chemotherapy and local radiotherapy. Growth velocity, height, sitting height, and subischial limb length SDS scores were analysed.

RESULTS

Growth failure secondary to isolated GH deficiency (GHD) developed in 7/17 patients. GHD occurred at a median (range) of 3.4 (1.3-9.9) years after radiotherapy tumour doses of 46 (40-50) Gy. Growth velocity, height, and subischial limb length SDS were significantly reduced in the GHD group and improved with GH therapy.

CONCLUSIONS

GH treatment resulted in a significant improvement in sitting height SDS. We discuss the unexpected improvement in spinal growth in survivors with GHD.

Heterozygous HESX1 mutations associated with isolated congenital pituitary hypoplasia and septo-optic dysplasia

We have previously shown that familial septo-optic dysplasia (SOD), a syndromic form of congenital hypopituitarism involving optic nerve hypoplasia and agenesis of midline brain structures, is associated with homozygosity for an inactivating mutation in the homeobox gene HESX1/Hesx1 in man and mouse. However, as most SOD/congenital hypopituitarism occurs sporadically, the possible contribution of HESX1 mutations to the aetiology of these cases is presently unclear. Interestingly, a small proportion of mice heterozygous for the Hesx1 null allele show a milder SOD phenocopy, implying that heterozygous mutations in human HESX1 could underlie some cases of congenital pituitary hypoplasia with or without midline defects. Accordingly, we have now scanned for HESX1 mutations in 228 patients with a broad spectrum of congenital pituitary defects, ranging in severity from isolated growth hormone deficiency to SOD with panhypopituitarism. Three different heterozygous missense mutations were detected in individuals with relatively mild pituitary hypoplasia or SOD, which display incomplete penetrance and variable phenotype amongst heterozygous family members. Gel shift analysis of the HESX1-S170L mutant protein, which is encoded by the C509T mutated allele, indicated that a significant reduction in relative DNA binding activity results from this mutation. Segregation analysis of a haplotype spanning 6.1 cM, which contains the HESX1 locus, indicated that only one HESX1 mutation was present in the families containing the C509T and A541G mutations. These results demonstrate that some sporadic cases of the more common mild forms of pituitary hypoplasia have a genetic basis, resulting from heterozygous mutation of the HESX1 gene.

Growth and endocrine disorders in multisystem Langerhans' cell histiocytosis

INTRODUCTION

Langerhans' cell histiocytosis is a rare disorder, with diabetes insipidus occurring in up to half of patients. Causes of growth failure include the illness itself, treatments used and growth hormone insufficiency.

PATIENTS AND METHODS

We identified all patients with an endocrinopathy secondary to Langerhans' cell histiocytosis (LCH). Growth data were analysed from all patients with multisystem involvement.

RESULTS

Of 144 patients with multisystem LCH, 50 had an endocrinopathy, 49 of whom had diabetes insipidus. Growth hormone insufficiency (GHI) was present in 21 patients, seven of whom had other anterior pituitary deficiencies as well (gonadotrophin deficiency + GHI n = 2, gonadotrophin deficiency + TSH deficiency + GHI n = 2, panhypopituitarism n = 3). GH insufficiency, the development of which appeared to be independent of pituitary radiation, occurred at a median age of 8.3 years (4.7-18 years) and at a median interval of 3.5 years (0-11.8 years) after diagnosis of LCH. The median height SDS at diagnosis of growth hormone insufficiency was -2.9. Thirteen of the patients with growth hormone insufficiency attained final height with a median height SDS of -1.2. The final height SDS of 15 patients without GH insufficiency was closer to target height SDS, but not statistically different from that of the GH insufficient group.

CONCLUSIONS

GH therapy significantly improves growth in GH insufficient patients with Langerhans' cell histiocytosis. Early institution of GH therapy may further improve height outcome. However, most children with Langerhans' cell histiocytosis regardless of endocrine function, failed to reach target height.

Hyponatraemia associated with lamotrigine in cranial diabetes insipidus

We report the cases of two children with cranial diabetes insipidus who were treated with lamotrigine for seizures and who had accompanying changes in desmopressin requirements. Lamotrigine is a new anticonvulsant chemically unrelated to other existing antiepileptic drugs. Studies suggest it acts at voltage-sensitive sodium channels and also decreases calcium conductance. Both of these mechanisms of action are shared by carbamazepine, which can cause hyponatraemia secondary to inappropriate secretion of antidiuretic hormone. It is possible that the effect of lamotrigine on fluid balance in the cases described is also centrally mediated.

Growth hormone treatment of Russell-Silver syndrome

Russell-Silver syndrome represents a special group of children with intrauterine growth retardation (IUGR) who do not experience catch-up growth and have characteristic dysmorphic features. They also have characteristics of abnormal growth hormone pulsatility, absence of catch-down growth after growth hormone therapy and inappropriate advancement of bone age during the middle childhood years. Data from children with Russell-Silver syndrome should certainly be analysed as a separate group from short children due to nondysmorphic IUGR. Initial data suggests that final height outcome will be improved by using pharmacological doses of biosynthetic human growth hormone. Indeed, the recent data supports the hypothesis of Blizzard's group in 1974 that if growth hormone became available in sufficient quantities, then final height could be altered in IUGR children. In addition, the early recognition and treatment of spontaneous nocturnal hypoglycaemia may well improve the educational achievement of such children.

Occult T3 toxicosis in McCune-Albright syndrome

We report a girl with McCune-Albright syndrome who presented with Cushing syndrome from adrenal hypersecretion and gonadotrophin-independent precocious puberty in the first year of life. At age 5, she failed to gain weight and was found to have hyperthyroidism, which was occult in that she had T3 toxicosis without a goitre or thyroid ultrasound abnormality. The latter has not been previously reported in McCune-Albright syndrome.

Absence of catch-down growth in Russell-Silver syndrome after short-term growth hormone treatment

We describe 3 children with Russell-Silver syndrome without growth hormone insufficiency who were treated with growth hormone for 2, 3. 7 and 6 years, showing a rapid growth acceleration. After cessation of growth hormone treatment, they grew at a normal rate without 'catch-down' growth. It may be possible that short intra-uterine growth retardation (IUGR) children with dysmorphic features respond to growth hormone therapy differently from non-dysmorphic IUGR short children. Short-term growth hormone treatment for children with Russell-Silver syndrome may avoid side effects and diminish costs.

Growth hormone treatment in growth hormone-sufficient and -insufficient children with intrauterine growth retardation/Russell-Silver syndrome

Fifty-eight short prepubertal children with IUGR received GH treatment (mean dose: 28 IU/m2/week) for a mean (SEM) period of time of 3.4 (0.13) years (range 1-4 years). They were subdivided according to their GH response to a pharmacological test. Twenty-six were GH insufficient (GHI) (group 1) and 32 were non-GHI (group 2). At the commencement of GH therapy mean chronological age was 6.1 (0.4) years in both groups, mean height SDS (SEM) was -3.5 (0.2) in group 1 and -3.6 (0.2) in group 2, mean growth velocity (GV) SDS (SEM) was -1.9 (0.3) in group 1 and -0.3 (0.2) in group 2. GH therapy induced significant growth acceleration throughout the follow-up period without any significant differences between the two groups. GV SDS (SEM) increased to +3.0 (0.5) in group 1 and to +3.7 (0.4) in group 2 (p < 0.05 compared to baseline) during the first year of therapy. Subsequently, the growth-promoting effects of GH therapy diminished with time but GV remained significantly higher than baseline. This growth enhancement produced a significant rise in height SDS (SEM) reaching - 1.4 (0.2) in group 1 and - 1.7 (0.2) in group 2 after 4 years. In conclusion, our data did not show any significant differences in the growth response to GH therapy between GH-sufficient and -insufficient IUGR children who were only distinguishable by their GH secretion. This indicates that the decision to treat a short IUGR child with GH therapy should not be based upon the GH response to a provocative test.

Premature thelarche: clinical follow-up and indication for treatment

Not only is the diagnosis of isolated premature thelarche difficult to distinguish from other variants of premature sexual maturation, but within the subgroups of isolated premature thelarche, there are probably at least two subgroups: "classical" and "atypical". We do not appreciate how potential treatment could affect each group, although it seems likely that those in the "classical" group would not have an indication for treatment. The longer-term follow-up of large numbers of patients is essential if we are to understand the long-term sequelae of this condition.

Basilar invagination as a sequela of multisystem Langerhans' cell histiocytosis

We report the presence of basilar invagination, an unexpected and previously undescribed abnormality of the skull base, in 7 of 38 long-term survivors of multisystem Langerhans' cell histiocytosis. The abnormality is acquired, but its pathogenesis is uncertain.

Sexually dimorphic and radiation dose dependent effect of cranial irradiation on body mass index

OBJECTIVES

To investigate the relation between cranial irradiation received during treatment for childhood leukaemia and obesity at final height.

DESIGN

Retrospective cross sectional study.

SETTING

Paediatric oncology centres at Great Ormond Street Hospital for Children and the Royal Marsden Hospital.

SUBJECTS

Survivors of childhood leukaemia who received cranial irradiation, were in continuous first remission, and had reached final height. An unirradiated group of patients from the United Kingdom acute lymphoblastic leukaemia XI trial was also included; these patients were in continuous first remission and had been followed for at least four years from diagnosis.

MAIN OUTCOME MEASURES

Body mass index standard deviation score (BMI z score) at final height for irradiated patients and at most recent follow up for unirradiated patients. Regression analysis was used to examine the effect on BMI z score of sex, age at diagnosis, and the dose of radiation received.

RESULTS

For cranially irradiated patients, an increase in the BMI z score at final height was associated with female sex and lower radiation dose, but not with age at diagnosis. Severe obesity, defined as a BMI z score of > 3 at final height, was only present in girls who received 18-20 Gy irradiation and had a prevalence of 8%. Both male and female unirradiated patients had raised BMI z scores at latest follow up and there was no association with age at diagnosis.

CONCLUSIONS

These data are further evidence for a sexually dimorphic and dose dependent effect of radiation on the human brain.

The spectrum of Silver-Russell syndrome: a clinical and molecular genetic study and new diagnostic criteria

The Silver-Russell syndrome (SRS) is characterised by severe intrauterine growth retardation, with a preserved head circumference, leading to a lean body habitus and short stature. Facial dysmorphism and asymmetry are considered typical features of the syndrome, although the range of phenotypic variance is unknown. Fifty seven subjects varying in age from 0.84 to 35.01 years, in whom the diagnosis of SRS had been considered definite or likely, were re-evaluated in a combined clinical and molecular study by a single observer (SMP). In 50 patients the clinical findings complied with a very broad definition of SRS. Notable additional findings included generalised camptodactyly seen in 11 (22%), many with distal arthrogryposis. Thirteen of the 25 males required genital surgery for conditions including hypospadias and inguinal hernia. Fourteen (36.8%) subjects above school age have received a statement of special educational needs. Molecular genetic analysis was performed in 42 subjects and has identified maternal uniparental disomy of chromosome 7 in four. The phenotype was generally milder with birth weights for one patient above and three below -2 SD from the mean. Two children had classical facial dysmorphic features, and two had a milder facial phenotype. Of relevance to the possible molecular mechanism underlying this condition, none of the four disomic patients had significant asymmetry.

Lipid profile, glucose tolerance and insulin sensitivity after more than four years of growth hormone therapy in non-growth hormone deficient adolescents

OBJECTIVE

To study the effects of long-term (> 4 years) growth hormone (GH) therapy on insulin sensitivity, glucose tolerance and lipid profile in non-GH deficient adolescents at completion of their growth.

SUBJECTS

Thirty non-GH deficient (15 'idiopathic' short stature, 8 intrauterine growth retardation, 7 partial GH deficiency in childhood but normal on retesting) were recruited, median (range) age 16.9 years (15-20.3) prior to ceasing their GH therapy. Their median (range) duration of GH treatment was 7.9 years (4-11). Insulin sensitivity was also recorded in 10 normal controls with a median (range) age of 20.5 years (18.4-22.3).

METHODS

Insulin sensitivity was assessed by a short insulin tolerance test in 18 patients on GH therapy and controls. It was repeated in 14 patients six months after stopping their GH therapy. A 3-h standard oral glucose tolerance test (OGTT) was performed in 19 patients on GH therapy, and repeated after 6 months off GH in 10 patients. Fasting lipids were also measured.

RESULTS

Insulin sensitivity index was significantly lower in the patients on GH therapy than in the controls, (median (range)) 3.7%/min (1.2-5.3) and 5.3%/min (3.8-6.2), respectively. Six months after termination of GH therapy, insulin sensitivity increased significantly from 3.6%/min (1.2-5) to 4. 8%/min (2.8-5.6). Fasting plasma insulin decreased significantly off GH therapy from 10.1 to 3.6 mU/l. The area under the insulin curve during the OGTT was also significantly higher on GH therapy. Apart from one patient with impaired glucose tolerance on GH treatment, plasma glucose concentrations remained within the normal range. No lipid abnormalities were recorded.

CONCLUSIONS

These data suggest that long-term GH therapy may cause insulin resistance in non GH deficient adolescents, but usually with neither impaired glucose tolerance nor hyperlipidaemia.

Multiple neonatal endocrinopathies in McCune-Albright syndrome

Two cases of McCune-Albright syndrome (MAS) are reported who presented in the neonatal period with profound failure to thrive, cardio-respiratory distress, precocious puberty and Cushing's syndrome for which both underwent bilateral adrenalectomy. Both girls had also bilateral nephrocalcinosis; in one case that may have been attributed to Cushing's syndrome, but in the second case the cause remained obscure with no obvious abnormality of calcium metabolism. The first girl had hydrocephalus which is uncommon in this condition and the second girl still failed to thrive at the age of 6 years, despite adequate caloric intake and hormonal manipulation. A constellation of other abnormal features are described. These cases illustrate the complexity of MAS which can become a life-threatening or a debilitating disorder.

Growth failure and pituitary function in CHARGE and VATER associations

Growth failure and anterior pituitary dysfunction are clinical features of the CHARGE and VATER associations. This study investigated pituitary dysfunction as a potential cause of poor growth in a series of four and three patients with the CHARGE and VATER associations, respectively, who had height standard deviation scores (SDS) less than-2. Five of the seven patients had associated subnormal growth velocity SDS. Patients were investigated with a combination of dynamic and basal endocrine tests. All patients were found to be normonatraemic and to have normal basal thyrotroph and stimulated corticotroph function. The one peripubertal patient had evidence of biochemical gonadotroph dysfunction. Although two patients had marginally low stimulated serum growth hormone responses to glucagon stimulation testing, this was associated with either normal growth velocity or normal serum insulin-like growth factor binding protein 3 (IGFBP-3) concentrations. Thus, somatotroph dysfunction could not be demonstrated unequivocally in any patient. Poor childhood linear growth in the CHARGE and VATER associations does not appear to be associated with pituitary dysfunction.

Pituitary dysfunction, morbidity and mortality with congenital midline malformation of the cerebrum

The purpose of this study was to review systematically a series of patients with congenital midline brain defects and pituitary dysfunction in early childhood and to quantitate the degree of dysfunction and clinical outcome. This study was a retrospective analysis of case notes of patients with pituitary dysfunction associated with either a midline cerebral anomaly and/or optic nerve hypoplasia. Forty patients were studied: 2 with semilobar holoprosencephaly, 2 with lobar holoprosencephaly, 18 with septo-optic dysplasia with an intact septum pellucidum, 7 with septo-optic dysplasia with an absent septum pellucidum, 7 with agenesis of the corpus callosum and 4 patients with isolated pituitary hypoplasia. An early age of diagnosis, feeding difficulties, neurodevelopmental disability, visual impairment and seizures were common occurrences. Despite disordered neuro-anatomy, most seizure disorders were caused by hypoglycaemia or hypernatraemia. Hypotensive/hypoglycaemic crises accounted for two out of three deaths within the study population. Most of patients had multiple pituitary hormone deficiency with growth hormone and adrenocorticotrophic hormone deficiency occurring most commonly. Unequivocal isolated hypothalamic dysfunction was an uncommon finding. In congenital midline brain malformation there is a spectrum of disordered neuro-anatomy associated with variable pituitary dysfunction. Clinical manifestations such as convulsions and developmental delay may be due to disordered metabolism and/or neuro-anatomy.

CONCLUSION

Children with congenital midline brain defects frequently manifest convulsions, neurodevelopmental disability and poor growth due to disordered metabolism and/or neuro-anatomy. Treating clinicians must be aware of the complex, dynamic neurological and metabolic nature of these patients and their potential for early demise.

Why is the retention of gonadotrophin secretion common in children with panhypopituitarism due to septo-optic dysplasia?

Septo-optic dysplasia (De Morsier syndrome) is a developmental anomaly of mid-line brain structures and includes optic nerve hypoplasia, absence of the septum pellucidum and hypothalamo-pituitary abnormalities. We describe seven patients (four female, three male) who had at least two out of the three features necessary for the diagnosis of septo-optic dysplasia. Four patients had hypopituitarism and yet normal gonadotrophin secretion: one of these also had anti-diuretic hormone insufficiency; three had isolated GH deficiency and yet had premature puberty, with the onset of puberty at least a year earlier than would have been expected for their bone age. In any progressive and evolving anterior pituitary lesion it is extremely unusual to lose corticotrophin-releasing hormone/ACTH and TRH/TSH secretion and yet to retain gonadotrophin secretion. GnRH neurons develop in the nasal mucosa and migrate to the hypothalamus in early fetal life. We hypothesise that the arrival of GnRH neurons in the hypothalamus after the development of a midline hypothalamic defect may explain these phenomena. Progress in spontaneous/premature puberty in children with De Morsier syndrome may have important implications for management. The combination of GH deficiency and premature puberty may allow an apparently normal growth rate but with an inappropriately advanced bone age resulting in impaired final stature. GnRH analogues may be a therapeutic option. In conclusion, some patients with De Morsier syndrome appear to retain the ability to secrete gonadotrophins in the face of loss of other hypothalamic releasing factors. The migration of GnRH neurons after the development of the midline defect may be an explanation.

Metaphyseal growth arrest lines in psychosocial short stature

Metaphyseal growth arrest lines are seen in children who experience significant physical stress such as infection or malnutrition over a sufficient period of time. These lines have not been reported previously in children with psychosocial short stature (PSS). Two boys and a girl with PSS with metaphyseal growth arrest lines on skeletal radiographs at the time of maximal stress in their homes are described. All three had reversible growth hormone insufficiency during admission, which is pathognomic for PSS. Multiple growth arrest lines in the distal end of the radius or vertebrae should alert clinicians to an alternative diagnosis in a child with growth hormone insufficiency. This may provide a clue to the diagnosis of occult PSS.

Recognition of children with psychosocial short stature: a spectrum of presentation

We describe 65 children (32F, 33M) with psychosocial short stature from 51 families. Average age was 6.6 years (range 0.9-16.5) and all but five were prepubertal. 67% of the patients lived in families with three or more children, but in 73% of cases the patient was the first or the second born child. 45% of the parents were divorced and in 31% of the families the father was unemployed. In 56 children, the birth weight was known and in only 29% was it above 3000 g; 21% were premature, 29% had features of low birth-weight syndrome (including four with Russell-Silver syndrome). Average birth weight was 2786 g (range 1650-4676). In all patients, the predominant reason for referral was growth failure. In 28% an environmental aetiology was suspected and in a further 29%, social or emotional problems were known to the referring physician but not suspected as the aetiology of the growth failure, despite social services involvement in 60% at the referral to our unit. At initial presentation in our clinic, we found additional features leading to the suspicion of psychosocial short stature; 54% abnormal eating pattern, 42% behaviour problems, 26% encopresis, 18% nocturnal enuresis and 12% inappropriate urination. During the observation period of a mean of 3.7 years, 27 (41%) of our patients were found to have been sexually or physically abused. In these 27 children hyperphagia, bizarre eating habits, behaviour problems, soiling and nocturnal enuresis were more common.

Frontonasal dysplasia with optic disc anomalies and other midline craniofacial defects: a report of six cases

The association of optic disc abnormalities with basal encephaloceles, specifically of the sphenoethmoidal type, and midline facial clefts has rarely been reported, although the association of midline facial clefts with encephaloceles is well described. We now report six cases of children, three males and three females, presenting with a sphenoethmoidal encephalocele, optic disc anomalies, midline facial clefting, hypertelorism, complete or partial agenesis of the corpus callosum, and endocrinological disturbances, including diabetes insipidus and pituitary dysfunction. This report underlines the importance of careful ophthalmic and endocrinological investigation of children with midline clefts associated with basal encephaloceles. These cases may represent a distinct entity within the spectrum of frontonasal dysplasia.

GH treatment induces sustained catch-up growth in children with intrauterine growth retardation: 7-year results

The anthropometric response to 7 years of GH treatment was assessed in 11 short children with Russell-Silver syndrome (RSS) and in 5 with non-dysmorphic intrauterine growth retardation (NRSS). GH treatment induced a significant increase (p < 0.0001) in the mean height standard deviation score (SDS) and at the 7-year follow-up a height appropriate for the natural history of final stature in NRSS/RSS was already attained. An appreciable growth rate was still present with final height being attained only in 2 girls. There was no significant change in height SDS for bone age. Multiple regression analysis showed only chronological age at the onset of GH treatment was a predictor of gain in height SDS during GH therapy. These findings suggest that early GH treatment improves long-term growth in children with NRSS/RSS. Moreover, final height attainment is required for a definitive assessment of the beneficial effect on adult stature. Bone age assessment is not a reliable parameter to predict final height outcome in these children.

Precocious pseudopuberty due to a granulosa cell tumour in a seven-month-old female

We describe a juvenile granulosa cell tumour resulting in pseudopuberty in an infant female. The progression of the clinical signs of puberty were non-consonant and the diagnosis was complicated by marginally elevated serum alpha-fetoprotein levels. The histological appearance of the resected tumour and binding of MIC2 antibody to tumour cells confirmed the diagnosis.