Novel mutations in LHX3 are associated with hypopituitarism and sensorineural hearing loss.

Homozygous loss-of-function mutations in the transcription factor LHX3 have been associated with hypopituitarism with structural anterior pituitary defects and cervical abnormalities with or without restricted neck rotation. We report two novel recessive mutations in LHX3 in four patients from two unrelated pedigrees. Clinical evaluation revealed that all four patients exhibit varying degrees of bilateral sensorineural hearing loss, which has not been previously reported in association with LHX3 mutations, in addition to hypopituitarism including adrenocorticotropic hormone deficiency and an unusual skin and skeletal phenotype in one family. Furthermore, re-evaluation of three patients previously described with LHX3 mutations showed they also exhibit varying degrees of bilateral sensorineural hearing loss. We have investigated a possible role for LHX3 in inner ear development in humans using in situ hybridization of human embryonic and fetal tissue. LHX3 is expressed in defined regions of the sensory epithelium of the developing inner ear in a pattern overlapping that of SOX2, which precedes the onset of LHX3 expression and is known to be required for inner ear and pituitary development in both mice and humans. Moreover, we show that SOX2 is capable of binding to and activating transcription of the LHX3 proximal promoter in vitro. This study therefore extends the phenotypic spectrum associated with LHX3 mutations to encompass variable sensorineural hearing loss and suggests a possible interaction between LHX3 and SOX2 likely to be important for development of both the inner ear and the anterior pituitary in human embryonic development.

The relationship between nocturnal urinary leptin and gonadotrophins as children progress towards puberty.

BACKGROUND/AIMS: Leptin is necessary for normal human pubertal development but its exact role in the period leading up to the onset of puberty has not been defined. This study has assessed the relationship between leptin and gonadotrophin secretion over time as children progress into puberty. SUBJECTS AND METHODS: Twenty children (13 boys and 7 girls) judged to be close to the initiation of puberty were recruited. Three consecutive first morning urine samples were collected from each subject each month over 6 months. At the end of the study, the children were classified into those who remained physically prepubertal (n = 7) and those that had advanced in puberty (n = 13). Leptin and gonadotrophins were measured by immunoradiometric and immunofluorometric assay, respectively. RESULTS: Total urinary leptin excreted over 6 months was higher in girls than in boys, both prepubertally and in early puberty, and in both sexes, was higher in those advancing into puberty than in those remaining prepubertal (girls 8.0 vs. 3.4 ng/l and boys 3.6 vs. 1.7 ng/l; both p < 0.05). In the whole group, when controlling for gender, there was a significant correlation between both leptin and luteinizing hormone (LH; r = 0.43, p < 0.001) and leptin and follicle-stimulating hormone (FSH; r = 0.32, p = 0.001). The possibility of a lead relationship was explored by pairing leptin values with the gonadotrophin values in the following month. Leptin was significantly correlated with FSH but not LH in both pre- and peripubertal children (prepubertal r = 0.45, p = 0.01; peripubertal r = 0.32, p = 0.01). CONCLUSIONS: This study has shown that in children approaching and progressing into puberty, leptin is associated with LH and FSH over the same time frame, and with FSH when leptin is acting as the lead hormone. These data imply that leptin is an important facilitator of the early phases of human puberty.

Phenotypic variation in constitutional delay of growth and puberty: relationship to specific leptin and leptin receptor gene polymorphisms.

OBJECTIVES: Constitutional delay of growth and puberty (CDGP) is a variant of normal pubertal timing and progress, often with dominant inheritance. It is likely that one or more genes will be associated with CDGP. Possible candidates are the leptin (L) and the leptin receptor (LR) genes, as the leptin axis links nutritional status to pubertal development. This study has assessed whether a) L or LR gene polymorphisms were associated with CDGP and b) the CDGP phenotype was influenced by these polymorphisms. DESIGN: Case-control and transmission disequilibrium tests were used to test genetic association of L and LR polymorphisms with CDGP. METHODS: We genotyped L (3'CTTT repeat) and LR polymorphisms (Gln > Arg substitution, exon 6) in 81 CDGP children and 94 controls in the UK and 88 CDGP children from the US and assessed the effect of genotype on their anthropometric characteristics. RESULTS: There was no association of these L or LR gene polymorphisms with CDGP. There was no difference in height or bone age delay within L or LR genotypes. However, UK CDGP children homozygous for the L short allele were heavier than heterozygotes and long allele homozygotes, with a similar trend in the US cohort. UK CDGP children with severe pubertal delay, who were thin, had significantly greater bone age delay and an increased frequency of parental pubertal delay than other groups and were less likely to be L short allele homozygotes. CONCLUSIONS: There was no association of specific L or LR polymorphisms with CDGP, but L short allele carriage influenced the phenotype within CDGP.

Community Attitudes and Practices of Urban Residents Regarding Predation by Pet Cats on Wildlife: An International Comparison.

International differences in practices and attitudes regarding pet cats' interactions with wildlife were assessed by surveying citizens from at least two cities in Australia, New Zealand, the UK, the USA, China and Japan. Predictions tested were: (i) cat owners would agree less than non-cat owners that cats might threaten wildlife, (ii) cat owners value wildlife less than non-cat owners, (iii) cat owners are less accepting of cat legislation/restrictions than non-owners, and (iv) respondents from regions with high endemic biodiversity (Australia, New Zealand, China and the USA state of Hawaii) would be most concerned about pet cats threatening wildlife. Everywhere non-owners were more likely than owners to agree that pet cats killing wildlife were a problem in cities, towns and rural areas. Agreement amongst non-owners was highest in Australia (95%) and New Zealand (78%) and lowest in the UK (38%). Irrespective of ownership, over 85% of respondents from all countries except China (65%) valued wildlife in cities, towns and rural areas. Non-owners advocated cat legislation more strongly than owners except in Japan. Australian non-owners were the most supportive (88%), followed by Chinese non-owners (80%) and Japanese owners (79.5%). The UK was least supportive (non-owners 43%, owners 25%). Many Australian (62%), New Zealand (51%) and Chinese owners (42%) agreed that pet cats killing wildlife in cities, towns and rural areas was a problem, while Hawaiian owners were similar to the mainland USA (20%). Thus high endemic biodiversity might contribute to attitudes in some, but not all, countries. Husbandry practices varied internationally, with predation highest where fewer cats were confined. Although the risk of wildlife population declines caused by pet cats justifies precautionary action, campaigns based on wildlife protection are unlikely to succeed outside Australia or New Zealand. Restrictions on roaming protect wildlife and benefit cat welfare, so welfare is a better rationale.

Behavioral and physical masculinization are related to genotype in girls with congenital adrenal hyperplasia.

Girls with congenital adrenal hyperplasia (CAH) exhibit behavioral masculinization. There is controversy about the roles of pre- and postnatal androgens, social factors, and chronic illness in its etiology. To assess the effect of chronic illness, we compared behavioral masculinity in 24 CAH girls and 25 diabetic girls aged 3-12 yr from Manchester using two sensitive questionnaires, and an overall masculinity score M (high = masculine) was derived. To assess the contributions of pre- and postnatal androgens, the CAH subjects were categorized into genotype groups (G) according to the reported severity of loss of CYP21 function: G1 (n = 10, null mutations), G2 (n = 9, intron 2G), G3 (n = 3, I172N), and G4 (n = 2, unknown loss of function). In CAH girls, relationships between G, Prader degree of genital masculinization at birth, bone age advance, and M were assessed. CAH girls were less feminine and more masculine than diabetic girls (P < 0.001), who were not significantly different from U.S. controls. Among the CAH girls, those in G1 and 2 were more genitally masculinized than those in G3 and 4 (P < 0.009) and had higher M (P < 0.025). M was negatively correlated with advanced bone age (r = -0.5; P = 0.02). CAH girls, but not diabetic girls, demonstrated behavioral masculinization. Both physical and behavioral masculinization were related to each other and to genotype, indicating that behavioral masculinization is a consequence of prenatal androgen exposure.

Intravenous valproate associated with circulatory collapse.

OBJECTIVE: To report a case of severe circulatory collapse following an intravenous injection of sodium valproate. CASE SUMMARY: A 5-year-old white girl, who was receiving vasopressor support, developed a severe circulatory collapse following an intravenous injection of valproate 480 mg. Her invasive arterial blood pressure dropped after valproate was started, and she went into cardiac arrest requiring full resuscitation including 2 doses of epinephrine. She was successfully resuscitated. DISCUSSION: To the best of our knowledge, this is the first case report of such severe circulatory collapse associated with intravenous valproate. Although hypotension has been reported following the use of intravenous valproate, severe circulatory compromise leading to cardiorespiratory arrest has not been previously described. An objective causality assessment using the Naranjo probability scale revealed that the adverse drug event was highly possible. CONCLUSIONS: In view of this patient's circulatory collapse associated with valproate, intravenous sodium valproate should be used with caution, particularly in hemodynamically unstable patients.

Variability in anterior pituitary size within members of a family with GH deficiency due to a new splice mutation in the GHRH receptor gene.

OBJECTIVE: Mutations in the GHRH receptor (GHRHR) gene (GHRHR) cause autosomal recessive isolated GH deficiency (IGHD), and are usually associated with anterior pituitary hypoplasia (APH) (defined as pituitary height more than 2 SDS below normal). We searched for GHRHR mutations and studied pituitary morphology in three prepubertal sibs with severe IGHD, who were born from consanguineous parents. DESIGN: We sequenced the 13 exons and the intron-exon boundaries of the GHRHR of the index patient. After identifying a novel mutation, we sequenced the same area in the other family members. In addition, we performed magnetic resonance imaging (MRI) study of the pituitary (at age 8, 4 and 3 years) in the three affected subjects. RESULTS: The three children were homozygous for a new GHRHR mutation that alters the second base of the invariant 5' splice site (GT) of intron 12 [IVS12 + 2T-->A]. The parents and an unaffected sibling were heterozygous for the same change. MRI did not show frank APH (by height criteria) in any of the subjects: pituitary height was normal (5.6 mm, +1.8 SDS) in the oldest sibling, and it was low but not below 2 SDS by age-adjusted criteria in the second (3 mm, -1.4 SDS), and third sibling (2.8 mm, -1.7 SDS). Calculated pituitary volume was below -2 SDS in the youngest patient. CONCLUSIONS: These data demonstrate that pituitary height may fall within 2 SDS from the norm in patients with severe IGHD due to a homozygous GHRHR mutation, and that pituitary size may vary within patients with identical mutations who belong to the same family.

Suppression of puberty with long-acting goserelin (Zoladex-LA): effect on gonadotrophin response to GnRH in the first treatment cycle.

BACKGROUND AND OBJECTIVES: Depot GnRH analogues are widely used in the treatment of precocious puberty, or suppression of relatively early puberty where growth or psychosocial well-being may be compromised. One example is Zoladex (Z goserelin 3.6 mg), which can be given every 4 weeks. This injection frequency may not always achieve adequate suppression of pubertal signs. A long-acting form, Zoladex-LA 10.8 mg, has now been introduced with a potential duration of action of 12 weeks. In order to assess the efficacy of Zoladex-LA in gonadotrophin suppression we have measured LH and FSH responses to GnRH at diagnosis and 8 and 12 weeks after injection in a group of children treated with Zoladex-LA for central precocious or early puberty. METHODS: Forty-nine children (40 girls) with clinical evidence of central precocious puberty (CPP) or early puberty (EP) were started on Zoladex-LA, either de novo (n = 29) or on changing from Zoladex. Ages at diagnosis ranged from 1.7 to 10.6 years (median 7.8 years). Twenty-three had a structural cause with abnormality on magnetic resonance/computerized tomography (MR/CT) head scan, nine had a syndrome or nonspecific brain injury, and in 17 the cause was idiopathic. RESULTS: At diagnosis, in the de novo group, median peak LH was 13.6 IU/l and median peak FSH was 12.0 IU/l. By 12 weeks gonadotrophins were suppressed to 0.9 and 0.8 IU/l, respectively. In the previously treated group, median peak LH at diagnosis was 12.8 IU/l and median peak FSH was 15.0 IU/l with suppression to 0.8 and 1.1 IU/l, respectively, at 12 weeks. In the latter group peak FSH was higher than peak LH at both 8 and 12 weeks (P < 0.05) and there was a significant rise in peak LH (P < 0.05) and FSH (P = 0.01) between 8 and 12 weeks. There was no correlation between age at diagnosis and peak LH or FSH at 8 or 12 weeks. Nevertheless, individual patients in both groups showed evidence of incomplete gonadotrophin suppression at 12 weeks. CONCLUSION: Zoladex-LA induces a significant reduction in gonadotrophins over 12 weeks. However, there are individuals, particularly those previously on Zoladex, in whom gonadotrophin suppression is waning by 12 weeks. As found with Zoladex, some children with precocious puberty treated with Zoladex-LA may require increased injection frequency, although correlation with clinical evidence of suppression needs to be studied further.

Leptin measurement in urine in children and its relationship to other growth peptides in serum and urine.

OBJECTIVE: Leptin has been implicated in the interaction between nutrition, energy balance and sexual maturation in humans. A non-invasive method of measuring leptin would greatly facilitate longitudinal studies of changes in leptin in normal children. The aim of this study was to evaluate the use of urinary leptin as a surrogate for serum leptin measurements. DESIGN: We have modified and validated a serum immunoradiometric assay (IRMA) kit for the measurement of leptin in urine, and subsequently investigated the relationship between urinary leptin and other growth-related proteins. METHODS: Cross-sectional study: urinary leptin, measured in the first morning urine voided and expressed as ng excreted overnight, and serum concentrations of leptin, IGF-I, IGF-II, IGFBP-3 and IGFBP-1 were determined in a cohort of 188 healthy schoolchildren aged 5-19 years (88 males, 100 females). Height, weight and pubertal status were assessed in all children. Longitudinal study: urinary levels of leptin, IGF-I and GH were measured daily in two adults (one male, one female) over a period of 6 weeks. RESULTS: The detection limit of this modified assay was 0.59 ng/L. The intra- and interassay coefficients of variation range was 4-8% and 4-9%, respectively. The recovery of recombinant leptin added to urine was 98-108%, and the assay had a recovery rate for serial dilution in the range of 106-112%. Urinary leptin correlated significantly with serum leptin (r = +0.65, P < 0.01). Urinary leptin showed similar changes through puberty to those of serum leptin, with levels rising in females throughout puberty, whereas in males levels peaked at G2/G3 then decreased. BMI SDS was the main determinant of urinary leptin, as it was for serum leptin. In the cross-sectional study urinary leptin correlated significantly with serum IGF-I (r = +0.41, P = 0.001), IGF-II (r = +0.19, P = 0.05), IGFBP-3 (r = +0.29, P = 0.001) and IGFBP-1 (r = -0.25, P = 0.001). In the adult study, leptin was also detected in urine with similar night-to-night variability to that found for IGF-I and GH. CONCLUSION: Urinary leptin is a valid marker of serum leptin concentrations, and therefore this non-invasive assay would be a useful tool for longitudinal assessment of changes in leptin in children.