A rational approach to short stature: focus on use and abuse of growth hormone

The abundant supply of recombinant growth hormone has raised interesting possibilities of several new applications. While supplementation of the missing hormone in patients with growth hormone deficiency is still the undisputed primary indication for its use, there is now convincing evidence of its usefulness in the therapy of short stature due to Turner syndrome and pre-transplant chronic renal failure in childhood. Numerous studies on patients with other causes of short stature have failed to show any significant benefit in final adult height. Social pressures notwithstanding, it is still premature to advocate the use of this expensive therapy for indications other than the three stated above especially since our understanding of potential long-term complications from such treatment is far from complete.

Hypophysiotropic somatostatin expression during postnatal development in growth hormone-deficient Ames dwarf mice: peptide immunocytochemistry

Based on previous findings that the inhibitory hypophysiotropic factor somatostatin (somatotropin-release-inhibiting hormone, SRIH) is markedly reduced in growth hormone (GH)-deficient transgenic or spontaneous Snell dwarf mice, the present study was undertaken to determine whether hypophysiotropic SRIH expression was reduced in a type of dwarf mouse (Ames, df/df) in which SRIH had not been assessed, and whether the supposed reduction was present throughout life or was the result of regression after initial normal differentiation. Brain sections from normal (DF/?) and df/df mice were immunostained for SRIH using both standard and 'Elite' avidin-biotin complex reagents (Vectastain kits, Vector Laboratories, Inc., Burlingame, Calif., USA). Selected adult mice were treated with intracerebroventricular colchicine to maximize SRIH retention in perikarya. The developmental pattern of hypophysiotropic SRIH was assessed in brains of DF/? and df/df mice at 1, 3, 7, 14, 21, 60, and 90 days (d) postnatally. SRIH-immunoreactive neurons in the anterior periventricular nucleus (PeN) were quantified at each age. Although the use of Elite reagents or Elite and colchicine pretreatment increased (p < 0.001) the number of immunoreactive cells that were detectable in adult (60- to 90-day-old) df/df mice, the number of PeN SRIH neurons was reduced to 28% (p < 0.01) in untreated, and to 47% (p < 0.01) in colchicine-treated, df/df compared with DF/?, mice. In other CNS areas, SRIH immunostaining was comparable for df/df and DF/? mice, including neuron numbers in the medial basal hypothalamus of untreated mice. In postnatal development, SRIH was detectable in median eminence (ME) terminals at birth in some mice of both phenotypes, and at 3 d in all DF/? mice; ME SRIH was detectable in all mice by 7 d. In PeN, SRIH cells were first detectable consistently in normals at 3 d, and in dwarfs at 7 d. In DF/? mice, numbers of immunoreactive SRIH perikarya increased from 3 to 21 d, then plateaued. In dwarfs, SRIH cell numbers increased through 14 d. Numbers of SRIH perikarya were lower in df/df than in DF/? at 7, 14, 21, 60, and 90 d (all p < 0.05 or less). Thus, in Ames dwarf mice, as in other GH-deficient models, SRIH is markedly reduced in hypophysiotropic, ME-projecting neurons. The developmental pattern of hypophysiotropic SRIH in Ames dwarf mice is different from that of hypophysiotropic dopaminergic (DA) neurons in these animals, which are also prolactin (PRL)-deficient. Although DA levels and cell numbers are reduced markedly in adult df/df mice, both parameters have been found to be comparable to those of DF/? mice for the first 2-3 weeks postnatally. The consistent PeN SRIH deficit in dwarfs may reflect the importance of GH feedback earlier in development, because GH production in normal mice begins before birth, whereas PRL is not detectable until 7 d postnatally. The findings indicate that absent GH production has a marked negative effect on differentiation and levels of peptide expression in hypophysiotropic SRIH neurons.

Growth hormone therapy in children with short stature: is bigger better or achievable?

The introduction of recombinant DNA-synthesized human growth hormone in the mid-1980s, and its attendant unlimited supply, have led to wider application of growth hormone therapy in children. Over the past decade, the efficacy of growth hormone treatment in patients with Turner syndrome and chronic renal insufficiency, two conditions in which growth hormone secretion is normal, in improving growth velocity and final height, has also led to the consideration of growth hormone therapy in children with idiopathic short stature. Although thousands of patients with idiopathic short stature are currently being treated with growth hormone, the limited overall results available at this time do not show a significant improvement in final adult height despite an improvement in short-term growth velocity. Potential reasons for this outcome include 1) skeletal age advancing more rapidly than height age, 2) heterogeneity of the patient population comprising idiopathic short stature, 3) inherent inaccuracies of methodological tools, such as measurement of predicted adult height, and 4) a subset of children with idiopathic short stature who may, in fact, have partial growth hormone insensitivity. From a psychological perspective, the consensus of investigations in non-clinic-referred populations of psychosocial function in children with short stature do not indicate a disadvantage compared with children of normal height when socio-economic status is taken into consideration. These results, in conjunction with the minimal gains reported in behavioural measurements in idiopathic short children treated with growth hormone, question the traditional rationale that augmentation of growth velocity results in improvement in psychosocial well-being.

[Growth hormone therapy in childhood. Growth hormone therapy in small children without growth hormone deficiency]

The availability of unlimited amounts of recombinant human growth hormone (rhGH) has now made it possible to investigate its growth-promoting effect in children in whom growth hormone production is not deficient. In girls suffering from the Ullrich Turner syndrome, treatment with rhGH increases final height by some 6 to 8 cm. An increase in growth rate has also been observed in children with renal insufficiency, and in children with intrauterine growth retardation. Favourable results have also been reported in children receiving glucocorticoids for such chronic conditions as rheumatoid arthritis, and in youngsters with hypochondroplasia. In a further group of children with various disorders an improvement in the growth rate has been observed, although nothing can yet be said about the outcome in terms of final height. To achieve an increase in growth rate, pharmacological doses of growth hormone higher than those used in children with growth hormone deficiency are necessary. For this reason, the risk of unwanted side effects might be higher than in the latter.

Ethical principles in federal regulations: the case of children and research risks

Ethical principles play an important part not only in the promulgation of regulations but also in their application, i.e., enforcement and adjudication. while traditional ethical principles--promotion of welfare, freedom, and fairness--play an important role in both elements of regulation, some other kinds of ethical principles are significant as well. Principles governing the structure of decision processes should shape the structure and actions of agencies; principles of wise application should govern the work of those whose responsibility it is to apply regulatory language to particular situations. These points are demonstrated by investigating a case study: federal regulations designed to protect children involved in scientific research applied to a placebo study of the effects of recombinant human growth hormone on children of extremely short stature.

Leg lengthening in Turner dwarfism

We have reviewed 16 patients treated by leg lengthening for various forms of Turner dwarfism with regard to the long period of healing and the complications. We consider that Turner dwarfism is a suitable indication for leg lengthening because of the moderate length deficit and the morphological appearance of the patients, and have introduced an improved programme of management to deal with the problems encountered.

Hemoglobin level is linked to growth hormone-dependent proteins in short children

Erythropoiesis was investigated in 32 children wih short stature and in eight children with skeletal dysplasia by studying blood hemoglobin in relation to growth and to serum concentrations of insulin-like growth factor I (IGF-I), IGF binding protein-3 (IGFBP-3), and erythropoietin (EPO) before, during, and after 12 months of recombinant human growth hormone (GH) treatment. Blood hemoglobin concentration was positively correlated with relative body height and with serum IGF-I and IGFBP-3 levels (P = .001 to .02), but not with the concentrations of EPO. The normal age-dependency of hemoglobin was lacking. Hemoglobin levels and their responses to GH treatment were similar in the patients with GH deficiency and those with normal GH secretion. Treatment with GH accelerated growth and elevated the concentrations of hemoglobin, IGF-I, and IGFBP-3. In the eight patients with skeletal dysplasia, body mass increased similarly, but gain in height was less than in the other patients, and the increase in hemoglobin was markedly pronounced. In this group, the correlations between hemoglobin, IGF-I, and IGFBP-3 were extremely close (r = 0.80 to 0.85, P = .031 to .008). These findings are in accord with earlier observations from in vitro and animal studies, and suggest that the GH-IGF axis is involved in the physiologic elevation of hemoglobin levels during childhood.

The Nakalanga syndrome in Kabarole District, Western Uganda

An acquired condition resulting in arrested growth was reported in the 1950s and 1960s from along the Nile near Jinja in eastern Uganda. This became known as Nakalanga dwarfism, and an association with onchocerciasis was postulated. After control of onchocerciasis through larvaciding in this area some 30 years ago, no new cases have been noted. We now report this condition from western Uganda where its appearance seems to be a relatively recent event. Thirty-one persons with short stature, 15 years of age and older, were identified through household surveys in an area of Kabarole district with a high prevalence of onchocerciasis. Cases identified were matched with controls selected for age and sex from the nearest household. Cases of Nakalanga syndrome weighed significantly less and were shorter than controls. The Z scores for weight-for-age, weight-for-height, height-for-age, and body mass index were significantly less among cases. Other clinical features observed among cases included absence of secondary sexual characteristics, skeletal deformities, dental caries, and mental retardation. All cases and 22 (79%) controls had microfilariae of Onchocerca volvulus in skin snips. All community members interviewed were aware of the Nakalanga syndrome, and 93% believed it to be acquired sometime after birth. The possible association with onchocerciasis is discussed.

[Bird headed dwarfism in Seckel syndrome. Nosologic difficulties]

Seckel syndrome is a clinical picture which associates four main features: intrauterine growth retardation, microcephaly often due to craniosynostosis, orofacial dysmorphology with bird headed appearance and variable mental retardation which is present after several months. Malformations of the central nervous system, limbs, and hair, may also be observed. On the basis of 78 cases reported in the literature, the authors discuss the validity of the morphological features of the syndrome. It is likely that the variability in the expressivity of each symptom explains its heterogeneity. According to the radiological abnormalities, three different forms of the syndrome have been described. Seckel syndrome is a genetic disorder with autosomal recessive inheritance. Its ethiopatogeny remains unclear. Hopefully linkage studies will allow to map the gene in order to determine the underlying abnormal protein.

Psychological complications of short stature in childhood. Some implications of the role of visual comparisons in normal and pathological development

This study examines the effect of short stature on the emotional development of a subgroup of children who were treated in psychoanalysis and psychotherapy. These children became capable of making accurate comparisons of body size in early latency as a result of advances in cognitive development. Recognizing their comparative smallness left them feeling vulnerable and humiliated. They responded with envy and rage toward normally endowed children and vindictively used their intellect to outwit and defeat others. They acted as if their suffering exempted them from ordinary social rules and expectations. Their preoccupation also resulted in arrests in cognitive and social development. Their distrust and intention to deceive and defeat posed particular problems for treatment. This outcome suggests that visual comparisons of size during early latency are implicated in pathological, and therefore in normal, development. Parallels are suggested between the subjective experiences of children in this group and the experiences of children with other kinds of physical deviations and compromising life circumstances.

[Biosynthetic growth hormone in the treatment of low stature in Turner syndrome]

Fifteen patients with Turner's syndrome with ages between 6.8 to 13.2 years were treated with biosynthetic growth hormone due to their low height. Twelve of them had a 45XO karyotype and three were mosaics; none had a Y line. They started with 0.7 IU/kg/week which were increased to 1.0 IU/kg/week if no height gain was observed during three months. The 15 patients have completed one year of treatment, 8 of them for two years. The height velocity increased significantly (p < 0.001) from 0.24 +/- 0.10 cm/month before treatment (mean +/- SD) to 0.48 +/- 0.09 in the first 12 months of treatment (height increased from 119.1 +/- 8.79 to 124.9 +/- 8.70). In the eight cases who have reached 24 months of treatment, the height velocity increased from 0.27 +/- 0.07 cm/month to 0.47 +/- 0.09 and 0.54 +/- 0.10 at 12 and 24 months respectively (p < 0.001 and p < 0.01 versus the pretreatment gain); height increased from 116.8 +/- 7.0 cm to 122.0 +/- 7.45 and 129.0 +/- 7.18. We found no adverse effects in the patients. It is concluded that the biosynthetic growth hormone treatment in Turner's syndrome can improve low height.

A boy with atrophic thyroiditis of prepubertal onset, who was positive for TSH-binding inhibitor immunoglobulins

A 12 year old boy was admitted to our hospital because of short stature. From the age of 7, his growth velocity decreased and he manifested intolerance to low temperatures, hoarseness, dry skin, and slowness of thought and physical movement. On admission, his height was 129.8 cm (-3 s.d.) and his body weight was 43.2 kg (-0.5 s.d.). His clinical features also included relaxation phase of tendon reflexes, periorbital puffiness and cold skin but no struma. His bone age was 9 years. His serum thyroxine (T4), triiodothyronine (T3), free T4 and free T3 were low, while his thyrotropin was high. He was positive for antithyroglobulin antibodies, antimicrosomal antibodies, and TSH-binding inhibitor immunoglobulins. He was diagnosed as having atrophic thyroiditis. We also determined the HLA haplotypes of his family members. His father's HLA haplotypes were A2, BW61(a) and A24, BW52(b), while his mother's haplotypes were A24, BW52(c) and A30, BW60(d). The HLA haplotypes of both the patient and his younger brother showed a and d, while the patient's elder brother's HLA haplotypes showed b and c. His family members all had normal thyroid function, but his father was positive for antimicrosomal antibodies. In summary, we describe a rare case where the onset of hypothyroidism was prepubertal, where the pathogenesis may have involved TSH-receptor blocking antibodies, and where the inheritance of the disease may have been from the paternal side of the family.

Adult stature and anthropomorphic measurements of patients with myelomeningocele

Children with myelomeningocele are extremely short, yet little data exists on adult stature and anthropomorphic measurements. We measured the recumbent length, weight, arm length, sitting height and calculated body mass index of 54 adults with myelomeningocele. Mid parental height was also calculated. Measurements were compared with normative data. Patient charts were reviewed for history of hydrocephalus. The 27 males and 27 females had a mean age of 24.8 +/- 5.7 years. The mean length for adult females was 141.9 +/- 12 cm and was 152.1 +/- 13 cm for males. Patients with thoracic level of lesions were shorter than those with lumbar level who were, in turn, shorter than those with sacral levels. Recumbent length, sitting height, arm length and arm span were significantly smaller than expected values. Recumbent length was smaller than mid parental height. Those with ventriculoperitoneal shunts, required for hydrocephalus, were shorter than these without a shunt.

CONCLUSION

Adults with myelomeningocele have significant short stature. Arm span is not an interchangeable measure with length for patients with myelomeningocele. Multiple factors are likely to be responsible for the observed short stature.

Prismatic cases: Laron syndrome (primary growth hormone resistance) from patient to laboratory to patient

Clinical investigations started in 1958 of a group of children with characteristics resembling GH deficiency, but who had extremely high levels of plasma GH, led to the description of the syndrome of primary GH resistance or insensitivity (Laron syndrome), the discovery of its molecular defect, and the clinical application of biosynthetic insulin-like growth factor-I. This syndrome is a unique model that enables study of the GH receptor, its signal transduction, and the comparison between the effects of GH and insulin-like growth factor-I.

GAPO syndrome in a child without dermal hyaline deposit

A 5-year-old girl with GAPO syndrome from India lacked PAS-positive hyaline material in the skin biopsy from thigh and scalp. The role of this pathological change, earlier reported by Wajntal et al. [1990] in the pathogenesis of GAPO syndrome, needs to be reexamined.

Comparison of school nurse and auxologist height velocity measurements in school children with short stature. (The Hackney Growth Initiative)

To examine the possible use of height velocity (HV) as a growth screening tool, annual HV data calculated from height measurements made by school nurses were compared with those based on an auxologist's measurements in 20 short school children. The subjects were 12 primary school children (seven girls, five boys) with a mean (+/- SD) age of 5.9(0.6) years and eight secondary school children (six girls, two boys) with a mean (+/- SD) age of 11.8 (0.4) years. Heights were measured by the school nurses, separated by an interval of 1 year. Mean HV of the primary school children when assessed by school nurses was 5.92 cm/year compared with 5.97 cm/year when assessed by the auxologist. Mean (+/- SD) HV standard deviation score (HVSDS) was 0.03 (0.97) and 0.10 (1.15) respectively. Mean HV of the secondary school children when assessed by school nurses was 6.04 cm/year compared with 5.63 cm/year when assessed by the auxologist. Mean (+/- SD) HVSDS was -0.8 (2.1) and -1.21 (1.54) respectively. Of eight children (three primary, five secondary) identified by the auxologist as having HV < 25th centile of Tanner and Whitehouse standards only four were identified by school nurses (one primary, three secondary). One child identified by school nurses to have HV < 25th centile was found by the auxologist to be above the 25th centile. We conclude that HV assessment may fail to identify significant pathology in the community and that accurate height measurement rather than HV should be the principal referral criterion.

Diagnostic imaging update in skeletal dysplasias

The mystique of bone dysplasias is gradually vanishing. A short historical overview introduces the subject of short stature. The pathogenesis and controversial classification of skeletal dysplasias are discussed and summarized in two tables; the use of different imaging modalities is laid out along the sequential diagnostic approach and review of common orthopedic complications. References to such advances in treatment as bone marrow transplantation, bone lengthening, and the encouraging positive effect of growth hormone therapy complete this updated revision.

[The Silver-Russell syndrome]

The authors describe a case of Silver-Russell Syndrome with severe deficit growth. They display the major and minor features of the syndrome, and discuss about the possible pathogenetic causes.