Isolated Growth Hormone Deficiency Patients Research Articles

Mutations in GH1 gene and isolated growth hormone deficiency (IGHD): A familial case of IGHD type I and systematic review

BackgroundIsolated growth hormone deficiency (IGHD) due to mutations in GH1 gene is a rare disease caused by deficient production of endogenous growth hormone (GH). MethodsWe reported the clinical manifestation and genetic diagnosis (whole exome sequencing [WES], nested PCR Sanger sequencing, and rtPCR) of a family with two children with IGHD type I. We conducted a systematic review of cases with IGHD and compared height, and treatment outcomes in subtypes of IGHD. ResultsThe patients were siblings born of nonconsanguineous parents from the Chinese Han population. The siblings both presented significantly short stature without other apparent abnormalities. The patients carry compound heterozygous mutations in GH1: a deletion and c.456 + 1G > A mutation that led to abnormal splicing. The systematic review identified 365 IGHD cases with GH1 mutations. Among these patients, their body height was most severely impaired in patients with IGHD type Ia, and the height standard deviation score decreased with the age of diagnosis in IGHD type Ia. Patients with IGHD type II had the longest duration of rhGH treatment, while patients with IGHD type Ib had the highest relative height improvement. ConclusionWe identified two patients with IGHD type I caused by compound heterozygotic GH1 deletion and splicing mutation. The analysis of previously published IGHD patients suggests differences in linear growth among subtypes of IGHD.

Porvair plc, UK

Isolated growth hormone deficiency (IGHD) due to mutations in GH1 gene is a rare disease caused by deficient production of endogenous growth hormone (GH).We reported the clinical manifestation and genetic diagnosis (whole exome sequencing [WES], nested PCR Sanger sequencing, and rtPCR) of a family with two children with IGHD type I. We conducted a systematic review of cases with IGHD and compared height, and treatment outcomes in subtypes of IGHD.The patients were siblings born of nonconsanguineous parents from the Chinese Han population. The siblings both presented significantly short stature without other apparent abnormalities. The patients carry compound heterozygous mutations in GH1: a deletion and c.456 + 1G > A mutation that led to abnormal splicing. The systematic review identified 365 IGHD cases with GH1 mutations. Among these patients, their body height was most severely impaired in patients with IGHD type Ia, and the height standard deviation score decreased with the age of diagnosis in IGHD type Ia. Patients with IGHD type II had the longest duration of rhGH treatment, while patients with IGHD type Ib had the highest relative height improvement.We identified two patients with IGHD type I caused by compound heterozygotic GH1 deletion and splicing mutation. The analysis of previously published IGHD patients suggests differences in linear growth among subtypes of IGHD.

Genetic spectrum and predictors of mutations in four known genes in Asian Indian patients with growth hormone deficiency and orthotopic posterior pituitary: an emphasis on regional genetic diversity.

Regional variation in prevalence of genetic mutations in growth hormone deficiency (GHD) is known. Study phenotype and prevalence of mutations in GH1, GHRHR, POU1F1, PROP1 genes in GHD cohort. One hundred and two patients {Isolated GHD (IGHD): 79; combined pituitary hormone deficiency (CPHD): 23} with orthotopic posterior pituitary were included. Auxologic, hormonal and radiological details were studied. All four genes were analysed in IGHD patients. POU1F1 and PROP1 were studied in CPHD patients. Of 102, 19.6% were familial cases. Height SDS, mean (SD) was - 5.14 (1.63). Peak GH, median (range) was 0.47ng/ml (0-6.59), 72.5% patients had anterior pituitary hypoplasia (APH). Twenty mutations (novel: 11) were found in 43.1% patients (n = 44, IGHD-36, CPHD-8). GHRHR mutations (n = 32, p.Glu72* = 24) were more common than GH1 mutations (n = 4) in IGHD cohort. POU1F1 mutations (n = 6) were more common than PROP1 mutations (n = 2) in CPHD cohort. With few exceptions, this prevalence pattern is contrary to most studies in world-literature. No patients with peak GH > 4ng/ml had mutations, signifying it as negative predictor. While many parameters were significant on univariate analysis, only positive family history and lower median peak GH levels were significant predictors of mutations on multivariate analysis in IGHD patients. At variance with world literature, we found reverse predominance of GHRHR over GH1 mutations, POU1F1 over PROP1 mutations and predominance of GHRHR p.Glu72* mutations thus re-affirming the regional diversity in GHD genetics. We report positive and negative predictors of mutations in GHD.

Порівняльна характеристика ауксологічних і гормональних показників пацієнтів із затримкою внутрішньоутробного розвитку та пацієнтів із соматотропною недостатністю

Мета — порівняльний аналіз ауксологічних і гормональних показників пацієнтів із низькорослістю внаслідок затримки внутрішньоутробного розвитку (ЗВУР) або соматотропної недостатності. Матеріал та методи. Проведено обстеження 84 дітей (55 хлопчиків і 29 дівчинок) передпубертатного віку з низькорослістю (<-2 SDS). У 34 пацієнтів встановлено наявність ізольованої соматотропної недостатності, у решти низько-рослість було пов’язано із затримкою внутрішньоутробного розвитку. На час обстеження всі пацієнти були в стані евтиреозу, лікування рекомбінантним гормоном росту (рГР) не отримували. Соматотропну функцію до- сліджували за допомогою фармакологічних тестів (інсулін, клонідин). Рівні гормону росту (ГР), інсуліноподібного чинника росту 1 (ІЧР‑1) досліджували методом твердофазного імуноферментного аналізу з використанням наборів «Immulate 2000 XPi». Рівні тиреотропного гормону (ТТГ), тироксину (Т4) вільного, трийодтироніну (Т3) вільного, ІЧР-зв’язуючого білка 3 (ІЧР-ЗБ‑3) досліджували імунорадіометричним методом за допомогою стандартних наборів (Immunotech® kit, Чехія). Результати. Усі діти з низькорослістю з ознаками ЗВУР на тлі однакового гестаційного віку мали суттєве зниження довжини та маси тіла на час народження порівняно з показниками дітей з ізольованою соматотропною недостатністю. Дефіцит зросту та маси зберігався й навіть зростав протягом тривалого часу (до 6-7-річного віку) в усіх обстежених. Ступінь відставання в рості та рентген-віці, швидкість росту та стадія статевого дозрівання в усіх обстежених достовірно не різнилися. У більшості (68,0%) пацієнтів зі ЗВУР без «спонтанного зростання» зафіксовано адекватний стимульований викид ГР, який достовірно перевищував пік викиду в дітей з ізольованим дефіцитом гормону росту, проте такі діти зберігали суттєве відставання в зрості та масі тіла. У решти пацієнтів зі ЗВУР (16 осіб, 32%) і в пацієнтів з ізольованим дефіцитом ГР встановлено різке зниження стимуляційного викиду ГР, що свідчить про наявність різкого дефіциту ГР. В усіх обстежених виявлено зниження рівнів ІЧР‑1 та ІЧР-ЗБ‑3 у сироватці крові. Зниження рівнів ІЧР-ЗБ‑3 було однаковим у пацієнтів усіх груп, а суттєве зниження рівня ІЧР‑1 спостерігали в дітей із соматотропною недостатністю (р<0,05) порівняно з показником пацієнтів зі ЗВУР із низьким викидом ГР. Висновки. У пацієнтів із затримкою внутрішньоутробного розвитку, які не мають «спонтанного зростання», можуть спостерігатися як нормальні, так і знижені показники стимульованого викиду гормону росту на тлі суттєво знижених показників ІЧР‑1 та ІЧР-ЗБ‑3. Дефіцит зросту, маси тіла, зниження рівнів ІЧР‑1 та ІЧР-ЗБ‑3 зберігаються тривалий час після народження дитини.

GH Supplementation Effects on Cardiovascular Risk in GH Deficient Adult Patients: A Systematic Review and Meta-analysis.

Background and Objective: The current meta-analysis aims at evaluating whether the existing clinical evidence may ascertain the effects of growth hormone (GH) replacement therapy on cardiovascular risk, both in isolated GH deficien-cy (GHD) and in compensated panhypopituitarism including GH deficit.Methods: Original articles published from 1991 to 2015 were searched on Medline (Pubmed). Among an overall number of 181 potentially suitable studies, 24 fulfilled the selection criteria and were included in the analysis. Data aggregation was car-ried out through the calculation of the absolute risk reduction. The meta-analysis was then conducted by means of a fixed-effects model, according to the heteroge-neity test (Chi-square statistic).Results: Fat-free mass (FFM) increase and fat mass (FM) reduction were found, together with a C-LDL reduction, a wide variation in glycaemia and a neutral effect on glycated haemoglobin (HbA1c) and blood pressure. These effects were valid both for isolated GHD patients and for those with compensated panhypopituitarism. The global out-come D showed a nonsignificant reduction of the overall cardiovascular risk (0.53; 95% C.I. -1.23, 2.85).Conclusion: Our meta-analysis shows no signnificatly positive trend in cardiovascular risk after both short and long-term GH supplementation therapy in adult GHD patients. However, a reduction of LDL cholesterol levels has been found. No differences were found between isolated GHD participants and those affected by panhypopituitarism well compensated since at least 3 months.

Long-Term Outcomes, Genetics, and Pituitary Morphology in Patients with Isolated Growth Hormone Deficiency and Multiple Pituitary Hormone Deficiencies: A Single-Centre Experience of Four Decades of Growth Hormone Replacement

Background: Growth hormone (GH) has been used to treat children with GH deficiency (GHD) since 1966. Aims: Using a combined retrospective and cross-sectional approach, we explored the long-term outcomes of patients with GHD, analysed factors influencing therapeutic response, determined persistence into adulthood, investigated pituitary morphology, and screened for mutations in causative genes. Methods: The files of 96 GH-deficient children were reviewed. In a subset of 50 patients, re-assessment in adulthood was performed, including GHRH-arginine testing, pituitary magnetic resonance imaging (MRI), and mutational screening for the growth hormone-1 gene (GH1) and the GHRH receptor gene (GHRHR) in isolated GHD (IGHD), and HESX1, PROP1, POU1F1, LHX3, LHX4, and GLI2 in multiple pituitary hormone deficiency (MPHD) patients. Results: GH was started at a height SDS of -3.2 ± 1.4 in IGHD patients and of -4.1 ± 2.1 in MPHD patients. Relative height gain was 0.3 SDS/year, absolute gain 1.6 SDS, and 1.2/2.6 SDS in IGHD/MPHD, respectively. Mid-parental target height was reached in 77%. Initial height SDS, bone age retardation and duration of GH replacement were correlated with height SDS gain. GHD persisted into adulthood in 19 and 89% of subjects with IGHD and MPHD, respectively. In 1/42 IGHD patients a GH1 mutation was detected; PROP1 mutations were found in 3/7 MPHD subjects. Anterior pituitary hypoplasia, combined with posterior pituitary ectopy and pituitary stalk invisibility on MRI, was an exclusive finding in MPHD patients. Conclusions: GH replacement successfully corrects the growth deficit in children with GHD. While the genetic aetiology remains undefined in most cases of IGHD, PROP1 mutations constitute a major cause for MPHD. Persistence of GHD into adulthood is related to abnormal pituitary morphology.

Identification of novel GHRHR and GH1 mutations in patients with isolated growth hormone deficiency

ObjectiveHuman growth is an elementary process which starts at conception and continues through different stages of development under the influence of growth hormone (GH) secreted by the anterior pituitary gland. Variation affecting the production, release and functional activity of GH leads to growth hormone deficiency (GHD), which is of two types: isolated growth hormone deficiency (IGHD) and combined pituitary hormone deficiency (CPHD). IGHD may result from mutations in GH1 and GHRHR while CPHD is associated with defects in transcription factor genes PROP1, POU1F1 and HESX1. The present study reports on the molecular screening of GHRHR and GH1 in IGHD patients. MethodsA total of 116 clinically diagnosed IGHD patients and 100 controls were enrolled for the study after taking informed consent. Family history was noted and 5ml blood sample was drawn. Anatomical and/or morphological pituitary gland alterations were studied using magnetic resonance imaging (MRI). DNA from blood samples was processed for screening the GHRHR and GH1 by Sanger sequencing. ResultsMean age at presentation of the 116 patients (67 males and 49 females) was 11.71±3.5years. Mean height standard deviation score (SDS) and weight SDS were −4.5 and −3.5 respectively. Nine (7.8%) were familial and parental consanguinity was present in 21 (19.8%) families. Eighty-three patients underwent MRI and morphological alterations of the pituitary were observed in 39 (46.9%). GH1 and GHRHR screening revealed eleven variations in 24 (21%) patients of which, four were novel deleterious, one novel non-pathogenic and six reported changes. ConclusionsGHRHR contributed more to IGHD in our patients which confirmed that GHRHR should be screened first before GH1 in our population. Identification of GH1 and GHRHR variations helped in defining our mutational spectrum which will play a crucial role in providing predictive and prenatal genetic testing to the patients.

Subjects with isolated GH deficiency due to a null GHRHR mutation eat proportionally more, but healthier than controls.

The GH/IGF-I axis has important interactions with the alimentary system and with the balance between energy intake (EI) and energy requirement (ER). Reduced EI has been described in adult-onset acquired GH deficiency (GHD). Individuals from the Brazilian Itabaianinha cohort, with isolated GHD (IGHD) due to a homozygous mutation (c.57+1G→A) in the GHRH receptor gene, are an ideal model to study the consequences of lifetime GHD. The purpose of this study is to evaluate EI and ER in this untreated IGHD cohort. Cross-sectional study of 24 adult IGHD patients and 23 controls from the same region, matched for age and gender. Estimated EI (EEI) was evaluated by dietary recall, and estimated ER (EER) by the equation of the Dietary Reference Intakes. Fat mass was assessed by DXA. Both EEI and EER were lower in IGHD than controls. However, when corrected by body weight, EEI was higher in IGHD (p = 0.005). IGHD individuals consume in percentage more proteins (p < 0.0001), less carbohydrates (p = 0.013), and equal amount of lipids in comparison to controls. The higher EEI per body weight suggests a possible increase of orexigenic mechanisms in untreated IGHD individuals, ensuring greater caloric intake, which would have adaptive advantages for small-sized individuals in environments with limited access to food. IGHD individuals seem to have a healthier dietary pattern than CO.

A novel gross indel in the growth hormone releasing hormone receptor gene of Indian IGHD patients

ContextCohort specific mutations in the growth hormone (GH1) and growth hormone-releasing hormone receptor (GHRHR) genes have been reported worldwide in isolated growth hormone deficiency (IGHD) patients. However, limited data is available on ethnically diverse Indian IGHD patients. ObjectiveThe aim of the study was to find GH1 and GHRHR gene mutations in Indian IGHD patients from two unrelated non-consanguineous families. DesignThe 5′ and 3′ untranslated regions (UTRs) and coding regions with splice sites of the GH1 and GHRHR genes were sequenced for all patients (n=6). Family members and 20 controls were evaluated for the sequence variants identified in the index patients. Online bioinformatics tools were used to confirm mutations and their pathogenicity. ResultsGHRHR gene mutations were observed in all patients. Interestingly, a novel indel g.30999250_31006943delinsAGAGATCCA was observed in both the unrelated families. Three patients were homozygous for the novel indel, two were homozygous for the previously reported p.E72X mutation and one was compound heterozygous with both the mutations (indel and p.E72X) in the GHRHR gene. The novel indel has resulted in the loss of 5′ regulatory region and exon 1 of the GHRHR gene impairing the GHRHR expression. All the normal family members were heterozygous either for the indel or p.E72X mutation. None of the patients had GH1 gene mutations. ConclusionsWe describe a novel gross indel in the GHRHR gene resulting in the loss of 5′ regulatory region and GHRHR exon 1 in four IGHD IB patients from two unrelated non-consanguineous Indian families.

Growth Hormone (GH-1) Gene Deletions in Children with Isolated Growth Hormone Deficiency (IGHD)

To detect growth hormone GH-1 gene deletions (6.7 kb, 7.6 kb, 7 kb) in familial/nonfamilial isolated growth hormone deficiency (IGHD) and note their clinical and investigative profile. Thirty (M16,F14) prepubertal IGHD patients aged 0.25 to 14 y, from 25 families were screened. Duration of growth failure, relevant history, clinical phenotype, and height SDS were recorded. Peak GH response to Clonidine (0.15 mg/m(2)), IGF-1, IGFBP-3 and pituitary/target gland hormones were studied. Genomic DNA of patients and family was analysed by PCR and DNA fragments were visualized on agarose gel electrophoresis. This series was divided into deletion +ve, Group I (n=12,40%) inclusive of six familial/six nonfamilial patients, and deletion -ve Group II (n=18,60%), 5 familial/13 nonfamilial cases; in total 11/30 were familial. Onset of growth failure was earlier in Group I (p<0.001) mean 1.1 vs 4.7 y. Mean height SDS was -7 vs. -4.5 in Groups I/II (p<0.01), age at presentation 5.1 vs 8.6 y. Overhanging forehead, prominent eyes, hypoplastic facies characterized Group I with FBS <50 mg/dl in 50% and very low peak GH <0.04 vs 2.04 ng/ml (p<0.001) in Group II. In both groups IGF-1 and IGFBP3 were low, other hormones were normal and MRI showed hypoplastic adenohypophysis. 40% had GH-1 gene deletion (6.7 kb deletion in 83%, 7.6 kb and a compound heterozygote in 8% each). In this series of 30 IGHD patients, frequency of GH-1 gene deletions (12/30) was 40%, and 54% among familial patients, and 31% with height SDS>-4. 83% had 6.7 kb deletion. Height SDS>-4, clinical phenotype, peak GH<1 ng/ml and hypoglycemia characterised IGHD Type IA.

Isolated GH deficiency: mutation screening and copy number analysis of HMGA2 and CDK6 genes

In most patients, the genetic cause of isolated GH deficiency (IGHD) is unknown. By identifying several genes associated with height variability within the normal population, three separate genome-wide association studies provided new candidate genes for human growth disorders. We selected two of them for genetic screening of our IGHD population. We aimed to determine whether high-mobility group A2 (HMGA2) and cyclin-dependent protein kinase 6 (CDK6) are involved in the pathogenicity of IGHD. We directly sequenced coding regions and exon-intron boundaries of the genes HMGA2 and CDK6 in 105 Caucasian IGHD patients from the Dutch HYPOPIT study. In addition, we developed a new probe set of multiplex ligation-dependent probe amplification for both genes in order to detect copy number variations. In one patient with classical IGHD phenotype, we identified a new heterozygous 20 bp deletion in the intronic region of HMGA2 (c.250-29_-9del), which was absent in the databases and healthy controls. Together, with recently published data concerning the 12q14 microdeletion syndrome, where patients with an HMGA2 haploinsufficiency had proportionate short stature, this study provides further support of the important role for HMGA2 in growth. In CDK6, we found only known polymorphisms. This study provides the first report of a deletion in the HMGA2 gene that might be related to IGHD. We suggest that this gene is investigated as a second screening in patients with a classical IGHD phenotype in which mutations in classical candidate genes have been excluded.

Adult height after growth hormone treatment in Japanese children with idiopathic growth hormone deficiency: analysis from the KIGS Japan database

To identify factors affecting adult height in Japanese patients with idiopathic growth hormone deficiency (GHD), who received growth hormone (GH) treatment during childhood. A retrospective pharmaco-epidemiological study of the effect of GH treatment on adult height standard deviation scores (SDS) was conducted in 374 Japanese patients with idiopathic GHD. During childhood, GH (0.146 +/- 0.023 mg/kg/week) was administered for a mean of 6.4 +/- 2.6 years. The mean adult height was 160.6 +/- 6.3 cm (-1.75 SD; n = 232) in boys and 146.9 +/- 7.3 cm (-2.20 SD; n = 158) in girls after GH therapy. The mean increases in height SDS in boys and girls with severe GHD were 2.13 SD and 1.66 SD, respectively (p < 0.05). These increases were greater than those observed in patients with moderate GHD and mild GHD. The mean adult height of male patients with GHD and gonadotropin deficiency (166.8 cm) was significantly higher (p < 0.05) than that of isolated GHD patients who were either receiving (159.1 cm) or not receiving (160.5 cm) gonadal suppression therapy. The mean adult heights of female patients were 149.6, 146.7, and 146.9 cm, respectively, and these values did not significantly differ. Linear multiple regression analyses of Japanese patients with severe GHD (n = 61) revealed three independent variables that influenced adult height: gonadotropin deficiency, initial height SDS and height velocity during the first year after the initiation of GH therapy.

Two Siblings with Isolated GH Deficiency Due to Loss-of-Function Mutation in the GHRHR Gene: Successful Treatment with Growth Hormone Despite Late Admission and Severe Growth Retardation-Case Report

Patients with growth hormone releasing hormone receptor (GHRHR) mutations exhibit pronounced dwarfism and are phenotypically and biochemically indistinguishable from other forms of isolated growth hormone deficiency (IGHD). We presented here two siblings with clinical findings of IGHD due to a nonsense mutation in the GHRHR gene who reached their target height in spite of late GH treatment. Two female siblings were admitted to our clinic with severe short stature at the age of 13.8 (patient 1) and 14.8 years (patient 2). On admission, height in patient 1 was 107 cm (−8.6 SD) and 117 cm (−6.7 SD) in patient 2. Bone age was delayed in both patients (6 years and 9 years). Clinical and biochemical analyses revealed a diagnosis of complete IGHD (peak GH levels on stimulation test was 0.06 ng/mL in patient 1 and 0.16 ng/mL in patient 2). Patients were given recombinant human GH treatment. Genetic analysis of the GH and GHRHR genes revealed that both patientscarried the GHRHR gene mutation p.Glu72X (c.214 G>T) in exon 3 in homozygous (or hemizygous) state. After seven years of GH treatment, the patients reached a final height appropriate for their target height. Final height was 151 cm (−1.5 SD) in patient 1 and 153 cm (−1.2 SD) in patient 2. In conclusion, genetic analysis is indicated in IGHD patients with severe growth failure and a positive family history. In spite of the very late diagnosis in these two patients who presented with severe growth deficit due to homozygous loss−of−function mutations in GHRHR, their final heights reached the target height.Conflict of interest:None declared.

Genetic Polymorphisms in the Locus Control Region and Promoter of GH1 Are Related to Serum IGF-I Levels and Height in Patients with Isolated Growth Hormone Deficiency and Healthy Controls

Background/Aims: Expression of the human growth hormone (GH) gene (GH1) is regulated by a locus control region (LCR) and the highly polymorphic GH1 promoter. We analyzed GH1 LCR/promoter single nucleotide polymorphisms (SNPs) in patients with isolated growth hormone deficiency (IGHD) in relation to clinical data. Methods: We directly sequenced the GH1 LCR/promoter of 62 Dutch IGHD patients without mutations or deletions in GH1 or GHRHR and of 72 controls with normal height. We related GH1 LCR/promoter SNPs to height, serum insulin-like growth factor 1 (IGF-I) levels and response to GH treatment. Results: In IGHD patients, promoter SNPs 6, 8 and 9 were associated with height and IGF-1 levels. In controls, SNPs 6 and 11 were associated with height. Homozygosity for the minor allele of SNP 9, associated with lower IGF-I levels in patients, was significantly more frequent among patients than among controls. Genotypes based on SNPs 6, 8, 9 and 11 explained 10.8% of IGF-I SDS variation in IGHD patients and 15.9% of height SDS variation in controls. Conclusion:GH1 Promoter SNPs 6, 8 and 9 were associated with height and IGF-1 levels among patients, and SNPs 6 and 11 with height in controls.

From isolated GH deficiency to multiple pituitary hormone deficiency: an evolving continuum – a KIMS analysis

To describe baseline clinical presentation, treatment effects and evolution of isolated GH deficiency (IGHD) to multiple pituitary hormone deficiency (MPHD) in adult-onset (AO) GHD. Observational prospective study. Baseline characteristics were recorded in 4110 patients with organic AO-GHD, who were GH naïve prior to entry into the Pfizer International Metabolic Database (KIMS; 283 (7%) IGHD, 3827 MPHD). The effect of GH replacement after 2 years was assessed in those with available follow-up data (133 IGHD, 2207 MPHD), and development of new deficiencies in those with available data on concomitant medication (165 IGHD, 3006 MPHD). IGHD and MPHD patients had similar baseline clinical presentation, and both groups responded similarly to 2 years of GH therapy, with favourable changes in lipid profile and improved quality of life. New deficiencies were observed in 35% of IGHD patients, which was similar to MPHD patients with one additional deficit other than GH. New deficiencies most often presented within the first year but were observed up to 6 years after GH commencement. Conversion of IGHD into MPHD was not predicted by aetiology, baseline characteristics, surgery or radiotherapy, whereas in MPHD additional deficits were predicted by age (P<0.001) and pituitary disease duration (P<0.01). Both AO-IGHD and -MPHD patients have similar baseline clinical presentation and respond equally well to 2 years of GH replacement. Hypopituitarism in adults seems to be a dynamic condition where new deficiencies can appear years after the initial diagnosis, and careful endocrine follow-up of all hypopituitary patients, including those with IGHD, is warranted.

Expanding the Spectrum of Mutations in GH1 and GHRHR: Genetic Screening in a Large Cohort of Patients with Congenital Isolated Growth Hormone Deficiency

It is estimated that 3-30% of cases with isolated GH deficiency (IGHD) have a genetic etiology, with a number of mutations being reported in GH1 and GHRHR. The aim of our study was to genetically characterize a cohort of patients with congenital IGHD and analyze their characteristics. A total of 224 patients (190 pedigrees) with IGHD and a eutopic posterior pituitary were screened for mutations in GH1 and GHRHR. To explore the possibility of an association of GH1 abnormalities with multiple pituitary hormone deficiencies, we have screened 62 patients with either multiple pituitary hormone deficiencies (42 pedigrees), or IGHD with an ectopic posterior pituitary (21 pedigrees). Mutations in GH1 and GHRHR were identified in 41 patients from 21 pedigrees (11.1%), with a higher prevalence in familial cases (38.6%). These included previously described and novel mutations in GH1 (C182X, G120V, R178H, IVS3+4nt, a>t) and GHRHR (W273S, R94L, R162W). Autosomal dominant, type II IGHD was the commonest form (52.4%), followed by type IB (42.8%) and type IA (4.8%). Patients with type II IGHD had highly variable phenotypes. There was no difference in the endocrinology or magnetic resonance imaging appearance between patients with and without mutations, although those with mutations presented with more significant growth failure (height, -4.7 +/- 1.6 SDS vs. -3.4 +/- 1.7 SDS) (P = 0.001). There was no apparent difference between patients with mutations in GH1 and GHRHR. IGHD patients with severe growth failure and a positive family history should be screened for genetic mutations; the evolving endocrinopathy observed in some of these patients suggests the need for long-term follow-up.

Genetic screening of a Dutch population with isolated GH deficiency (IGHD)

Five per cent to 30% of cases of idiopathic isolated GH deficiency (IGHD) have first-degree relatives with short stature, which is suggestive of a genetic aetiology. The HYPOPIT study aimed to obtain an overall picture of gene encoding pituitary GH (GH1) and gene encoding GH releasing hormone-receptor (GHRHR) defects in a Dutch IGHD cohort and to relate them with clinical parameters. Genetic analysis was performed of exons and exon-intron boundaries of GH1 and GHRHR in 89 Caucasian IGHD patients from 81 families, using denaturing high-performance liquid chromatography (dHPLC), DNA sequencing and multiplex ligation-dependent probe amplification. In addition, we performed functional studies on novel identified GH1 exonic variants. Five different heterozygous GH1 mutations were present in 5 out of 81 participating families (6.1%), whereas no mutations in GHRHR were found. Patients with IGF-I SDS < -4.0 and peak GH levels < 5.7 mU/l had a mutation frequency of 40%, in contrast to 6.8% in patients with only one criterion, and 0.0% in patients with none of these criteria (P = 0.00007). Five new GH1 and two GHRHR variants were also identified; two of them (GH1 F92L and D153H) caused a marked reduction of GH secretion in vitro. GH1 and GHRHR mutations are rare in Caucasian Dutch IGHD patients, which suggests the involvement of other genetic determinants in the aetiology of IGHD. IGF-I < -4.0 and peak GH levels < 5.7 mU/l are strong predictors of GH1 mutations in the studied population.

Antipituitary Antibodies in Dutch Patients with Idiopathic Hypopituitarism

Background: Despite extensive research, in the majority of patients with isolated growth hormone deficiency (IGHD) and multiple pituitary hormone deficiency (MPHD), the cause of their clinical picture remains unknown. Recent articles suggest that some cases of idiopathic growth hormone deficiency might be explained by a silent form of autoimmune hypophysitis based on the presence of antipituitary antibodies (APA) at high titers (>1:8). Methods: We collected clinical data and serum from 71 patients participating in the Dutch HYPOPIT study. APA screening in 40 IGHD patients and 31 MPHD patients was performed by an indirect immunofluorescence method. APA, when present, were related to clinical and morphological pituitary findings. Results: APA were present at high titers in 7 of 31 MPHD patients (23%) and 1 of 40 IGHD patients (2.5%). Among APA-positive MPHD patients, apart from growth hormone deficiency, all patients of pubertal age had gonadotroph defi- ciency, all had thyroid hormone deficiency and 50% had ACTH deficiency. Conclusion: The high frequency of APA in our idiopathic MPHD population indicates that, in 23% of the patients diagnosed with idiopathic MPHD, the hormone deficiencies might actually be caused by a silent form of autoimmune hypophysitis. Screening for APA should therefore be considered in all patients with ‘idiopathic’ MPHD.

A Functional Common Polymorphism in the Vitamin D-Responsive Element of theGH1Promoter Contributes to Isolated Growth Hormone Deficiency

Causal mutations have been detected only in a minority of isolated GH deficiency (IGHD) patients. Idiopathic IGHD might be the result of the interaction between several low-penetrance genetic factors and the environment. The aim of this study was to test the contribution to IGHD of genetic variations in the GH1 gene regulatory regions. A case-control association study was performed including 118 sporadic IGHD patients with a nonsevere phenotype (height -4/-1 sd score and partial GH deficiency) and two control groups, normal stature (n=200) and short-stature individuals with normal GH secretion (n=113). Seven single-nucleotide polymorphisms in the GH1 promoter, one in the IVS4 region, and two in the locus control region were analyzed. The -57T allele within the vitamin D-responsive element showed a positive significant association when comparing patients with normal (P=0.006) or short stature (P=0.0011) controls. The genotype -57TT showed an odds ratio of 2.93 (1.44-5.99) and 2.99 (1.42-6.31), respectively. The functional relevance of the -57 variation was demonstrated by the luciferase assay in the presence of vitamin D. The vitamin D-induced inhibition of luciferase activity was significantly (P=0.012) stronger for the promoter haplotype carrying the associated variation -57T [haplotype #1 (hp#1)] with respect to hp#2, bearing -57G. Replacement of the T with a G at -57 on hp#1 abolished the repression, demonstrating that the T at position -57 is necessary to determine the greater vitamin D-induced inhibitory effect of hp#1. EMSA experiments showed a different band-shift pattern of the T and G sequences. The common -57G-->T polymorphism contributes to IGHD susceptibility, indicating that it may have a multifactorial etiology.

Adult Height in Patients with Permanent Growth Hormone Deficiency with and without Multiple Pituitary Hormone Deficiencies

It has been reported that patients with multiple pituitary hormone deficiencies (MPHDs) achieve a greater final height, compared with patients with isolated GH deficiency (IGHD). However, the outcome of patients with permanent GH deficiency (GHD) has not yet been reported. The objectives of the study were to evaluate and compare adult height data and the effect of spontaneous or induced puberty after long-term treatment with GH in young adults with either permanent IGHD or MPHD. This was a retrospective multicenter study conducted in university research hospitals and a tertiary referral endocrine unit. Thirty-nine patients with IGHD (26 males, 13 females) and 49 with MPHD (31 males, 18 females), diagnosed at a median age of 7.7 and 6.9 yr, respectively, were reevaluated for GH secretion after adult height achievement (median age 17.6 and 19.8 yr). The diagnosis of permanent GHD was based on peak GH levels less than 3 microg/liter after an insulin tolerance test or peak GH levels less than 5 microg/liter after two different tests. Fifteen subjects had idiopathic GHD and seventy-three had magnetic resonance imaging evidence of congenital hypothalamic-pituitary abnormalities. Height sd score (SDS) was analyzed at diagnosis, the onset of puberty (either spontaneous or induced), and the time of GH withdrawal. The subjects with IGHD entered puberty at a median age of 12.6 yr (females) and 13.4 yr (males). Puberty was induced at a median age of 13.5 and 14.0 yr, respectively, in males and females with MPHD. Median height SDS at the beginning of puberty was similar in the IGHD and MPHD subjects. Total pubertal height gain was similar between patients with IGHD or MPHD. Median adult height was also not significantly different between IGHD and MPHD patients (males, 168.5 vs. 170.3 cm; females, 160.0 vs. 157.3 cm). The adult height SDS of the IGHD subjects was positively correlated with height at the time of diagnosis and with total pubertal height gain. Conversely, the adult height SDS of the MPHD subjects was positively correlated with both the duration of GH treatment and height SDS at the time of GHD diagnosis. Adult height in patients with permanent IGHD and spontaneous puberty is similar to adult height in patients with MPHD and induced puberty.