Patricia A. Donohoue

Summary of Consensus Statement on Intersex Disorders and Their Management

Advances in understanding of genetic control of sexual determination and differentiation, improvements in diagnostic testing and surgical genital repair, and the persistent controversies inherent to clinical management were all compelling factors that led to the organization of an international consensus conference. The goals were to acknowledge and discuss the more controversial issues in intersex management, provide management guidelines for intersex patients, and identify and prioritize questions that need additional investigation. This is a summary statement.nnAdvances in molecular genetic causes of abnormal sexual development and heightened awareness of the ethical and patient-advocacy issues mandate reexamination of existing nomenclature for patients with intersex.1 Terminology such as “pseudohermaphroditism” is controversial, potentially pejorative to patients,2 and inherently confusing. Therefore, the term “disorders of sex development” (DSD) is proposed to indicate congenital conditions with atypical development of chromosomal, gonadal, or anatomic sex.nnAdditional rationale for new classification is the need for modern categorization to integrate the modern molecular genetic aspects, to maximize precision when applying definitions and diagnostic labels,3 and to meet the need for psychologically sensitive yet descriptive medical terminology. Nomenclature should be flexible enough to incorporate new information, robust enough to maintain a consistent framework, use descriptive terms, reflect genetic etiology, accommodate phenotypic variation spectrum, and be useful for clinicians, scientists, patients, and families. Hence, we propose a new classification (see “Consensus Statement on Management of Intersex Disorders”4 in this months issue of Pediatrics Electronic Edition ).nnThree traditionally conceptualized domains of psychosexual development are gender identity (ones self-representation [ie, male or female]), gender role (sexually dimorphic behaviors within the general population, such as toy preferences, aggression, and spatial ability), and sexual orientation (direction[s] of erotic interest). Gender dissatisfaction denotes unhappiness with assigned sex and may result in gender self-reassignment. Psychosexual developmental factors relate to parental psychopathology, parent-child … nnAddress correspondence to Peter A. Lee, MD, PhD, Department of Pediatrics, MC-H085, Penn State College of Medicine, Milton S. Hershey Medical Center, Box 850, 500 University Dr, Hershey, PA 17033-0850. E-mail: plee{at}psu.edu

A meta-analytic investigation of linkage and association of common leptin receptor (LEPR) polymorphisms with body mass index and waist circumference

Methods: We analyzed data pooled from nine studies on the human leptin receptor (LEPR) gene for the association of three alleles (K109R, Q223R and K656N) of LEPR with body mass index (BMI; kg/m2) and waist circumference (WC). A total of 3263 related and unrelated subjects from diverse ethnic backgrounds including African-American, Caucasian, Danish, Finnish, French Canadian and Nigerian were studied. We tested effects of individual alleles, joint effects of alleles at multiple loci, epistatic effects among alleles at different loci, effect modification by age, sex, diabetes and ethnicity, and pleiotropic genotype effects on BMI and WC.Results: We found that none of the effects were significant at the 0.05 level. Heterogeneity tests showed that the variations of the non-significant effects are within the range of sampling variation.Conclusions: We conclude that, although certain genotypic effects could be population-specific, there was no statistically compelling evidence that any of the three LEPR alleles is associated with BMI or WC in the overall population.

Accelerated growth rates in children treated with growth hormone after renal transplantation.

To determine the usefulness of growth hormone treatment among children with renal allografts, we treated nine children with functioning renal transplants who were less than 16 years of age and had poor growth. The nine children, who were aged 12.6 +/- 4.0 years, had (1) heights greater than 2.5 SD less than the mean for age, (2) growth rates less than or equal to 5 cm/yr, and (3) additional growth potential, as assessed by bone age (8.9 +/- 2.8 year). Insulin-like growth factor I, thyrotropin, and thyroid hormone levels were normal for age in all children. Growth hormone treatment increased growth rates from 1.9 +/- 1.1 cm/yr to 7.2 +/- 1.8 cm/yr without accelerating skeletal maturation and without advancing pubertal status. During growth hormone treatment, serum creatinine concentration rose from 140 +/- 50 to 190 +/- 80 mumol/L (1.6 +/- 0.6 to 2.1 +/- 0.9 mg/dl) (p less than 0.05), and creatinine clearances decreased from 0.79 +/- 0.37 to 0.58 +/- 0.30 ml/sec per 1.73 m2 (47 +/- 22 to 35 +/- 18 ml/min per 1.73 m2) (p less than 0.05) but then remained stable. Growth rates of two patients returned to pretreatment rates when growth hormone treatment was discontinued after 5 and 7 months because of increased serum creatinine values. Growth hormone treatment may be useful as adjunctive therapy for increasing growth rates in selected children with renal allografts who have poor growth; however, serum creatinine concentrations should be closely monitored during such treatment.

Plasma leptin in diabetic and insulin-treated diabetic and normal rats☆

Adipose tissue leptin mRNA levels are decreased by food deprivation or induction of insulin-deficient diabetes. To determine whether plasma leptin concentrations are similarly affected, whether treatment of diabetes with insulin restores plasma leptin, and whether this requires restoration of body weight (lost as a result of diabetes) and/or normalization of glycemia, we measured plasma leptin concentrations in control, untreated streptozotocin (STZ)-diabetic, and insulin-treated STZ-diabetic rats. Plasma leptin was markedly reduced in untreated STZ-diabetic rats. Insulin treatment for 4 to 17 days increased plasma leptin approximately twofold above control levels. However, despite the hyperleptinemia, insulin-treated diabetic rats gained weight at a rate equal to that of sham-treated controls. Epididymal adipose tissue leptin mRNA levels in 17-day insulin-treated diabetic rats were equal to but did not exceed sham-control levels, unlike plasma leptin. Plasma glucose concentrations in insulin-treated STZ-diabetic rats were lower than in sham controls. Therefore, to determine whether hypoglycemia may be important in increasing plasma leptin, we measured plasma leptin levels in diabetic rats infused with insulin for 3 hours along with a variable-rate glucose infusion targeting glycemia to 200 or 40 mg/100 mL. Plasma leptin rapidly increased in these rats irrespective of target glycemia. Plasma leptin also increased rapidly in normal rats infused with insulin and glucose (target glycemia, 200 mg/100 mL). We conclude that plasma leptin concentrations are markedly reduced under conditions of insulin deficiency and rapidly increased by insulin treatment. The increase in plasma leptin does not require restoration of body weight and, under glucose clamp conditions, does not depend on target glycemia. Hyperleptinemia in insulin-treated diabetic rats is not explained on the basis of steady-state leptin mRNA levels, at least as reflected in epididymal fat.

Sympathetic inhibition, leptin, and uncoupling protein subtype expression in normal fasting rats

To further investigate neural effects on leptin and uncoupling proteins (UCPs), we studied in vivo perturbations intended to block adrenergic input to peripheral tissues. We examined plasma leptin, leptin mRNA, and adipose and muscle UCP subtype mRNA in rats treated with alpha-methyl-p-tyrosine methyl ester (AMPT-ME), which inhibits catecholamine synthesis and 6-hydroxydopamine (6HDA), which is toxic to catecholinergic nerve terminals but, unlike AMPT-ME, does not enter the central nervous system. Intraperitoneal AMPT-ME, 250 mg/kg, was administered at 1800 and 0700 the following day, and rats were killed at 1200-1400. All rats were fasted with free access to water during this time. Intraperitoneal AMPT-ME increased plasma leptin by 15-fold, increased interscapular brown adipose tissue (IBAT) and epididymal fat leptin mRNA by 2- to 2.5-fold, and also increased plasma insulin and glucose concentrations. Intraperitoneal AMPT-ME decreased IBAT UCP-3 mRNA to 40% of control, while it increased epididymal adipose UCP-3 mRNA approximately twofold. Intravenous AMPT-ME, 250 mg/kg, administered to conscious rats for 5 h decreased lumbar sympathetic nerve activity, increased plasma leptin (5.89 +/- 1.43 compared with 2.75 +/- 0.31 ng/ml in vehicle-treated rats, n = 7, P < 0.05), and decreased cardiac rate with no sustained change in blood pressure. Intraperitoneal 6HDA, 100 mg/kg, as a single dose at 1800, increased plasma leptin approximately twofold after 18-20 h, increased IBAT (but not epididymal fat) leptin mRNA by two- to threefold, and decreased IBAT UCP-3 mRNA to 30-40% of control. Neither AMPT-ME nor 6HDA significantly altered mRNA encoding gastrocnemius muscle UCP-3, IBAT UCP-1, or IBAT and epididymal UCP-2. In summary, AMPT-ME and 6HDA increased plasma leptin and upregulated leptin mRNA expression. AMPT-ME also resulted in complex tissue and subtype-specific modulation of adipose UCP mRNA. These data are consistent with interaction between leptin and sympathetic nerve activity (SNA) in regulation of fat cell energy utilization. However, the in vivo modulation of leptin and UCPs appears complex and, beyond a causal effect of SNA per se, may depend on concurrent changes in plasma insulin, glucose, and circulatory hemodynamics.To further investigate neural effects on leptin and uncoupling proteins (UCPs), we studied in vivo perturbations intended to block adrenergic input to peripheral tissues. We examined plasma leptin, leptin mRNA, and adipose and muscle UCP subtype mRNA in rats treated with α-methyl- p-tyrosine methyl ester (AMPT-ME), which inhibits catecholamine synthesis and 6-hydroxydopamine (6HDA), which is toxic to catecholinergic nerve terminals but, unlike AMPT-ME, does not enter the central nervous system. Intraperitoneal AMPT-ME, 250 mg/kg, was administered at 1800 and 0700 the following day, and rats were killed at 1200-1400. All rats were fasted with free access to water during this time. Intraperitoneal AMPT-ME increased plasma leptin by 15-fold, increased interscapular brown adipose tissue (IBAT) and epididymal fat leptin mRNA by 2- to 2.5-fold, and also increased plasma insulin and glucose concentrations. Intraperitoneal AMPT-ME decreased IBAT UCP-3 mRNA to 40% of control, while it increased epididymal adipose UCP-3 mRNA approximately twofold. Intravenous AMPT-ME, 250 mg/kg, administered to conscious rats for 5 h decreased lumbar sympathetic nerve activity, increased plasma leptin (5.89 ± 1.43 compared with 2.75 ± 0.31 ng/ml in vehicle-treated rats, n = 7, P < 0.05), and decreased cardiac rate with no sustained change in blood pressure. Intraperitoneal 6HDA, 100 mg/kg, as a single dose at 1800, increased plasma leptin approximately twofold after 18-20 h, increased IBAT (but not epididymal fat) leptin mRNA by two- to threefold, and decreased IBAT UCP-3 mRNA to 30-40% of control. Neither AMPT-ME nor 6HDA significantly altered mRNA encoding gastrocnemius muscle UCP-3, IBAT UCP-1, or IBAT and epididymal UCP-2. In summary, AMPT-ME and 6HDA increased plasma leptin and upregulated leptin mRNA expression. AMPT-ME also resulted in complex tissue and subtype-specific modulation of adipose UCP mRNA. These data are consistent with interaction between leptin and sympathetic nerve activity (SNA) in regulation of fat cell energy utilization. However, the in vivo modulation of leptin and UCPs appears complex and, beyond a causal effect of SNA per se, may depend on concurrent changes in plasma insulin, glucose, and circulatory hemodynamics.

Two distinct areas of unequal crossingover within the steroid 21-hydroxylase genes produce absence of CYP21B

We mapped crossover sites in chimeric, recombinant CYP21 genes from six patients with salt-losing congenital adrenal hyperplasia (CAH). Nucleotide sequences unique to the CYP21A pseudogene or to the active CYP21B gene were mapped using gene-specific restriction sites and oligonucleotide hybridizations. Each chimeric CYP21 gene in the CYP21-deletion linked haplotypes contained sequences near the 5 end that were characteristic of CYP21A and only a single transition from sequences of CYP21A to those of CYP21B at the 3 end. The transitions all occurred within either of two discrete regions (+470 to +999 and +1375 to +1993). All eight chimeric CYP21 genes coupled with HLA-Bw47 in five unrelated patients had the CYP21A-CYP21B sequence transition within the same gene region (+1375 to +1993). One of the three other CYP21B deletion haplotypes (HLA-B7) had a sequence transition within this same region, while in the other two haplotypes (HLA-B61 and HLA-B18) the transition occurred between base pairs +470 and +999. By contrast, both CYP21 genes in a haplotype containing a gene conversion of CYP21B to CYP21A contained apparent transitions between sequences of CYP21A and CYP21B. We conclude that a single, unequal crossingover between the CYP21A and the CYP21B genes yields deletion of the active CYP21 gene and salt-losing CAH and that these crossingovers do not occur randomly within the CYP21 genes of our patients.

Pituitary gigantism caused by growth hormone excess from infancy

A 2 1/4-year-old boy with pituitary gigantism had a large pituitary macroadenoma. Gross tumor removal has prevented further visual losses, but he has had persistent hypersecretion of growth hormone and prolactin. Treatment with somatostatin analog has decreased both hormone secretion and growth velocity.

Endocrine Evaluation of Adults with Mild Hypospadias

The goal of our study was to determine the frequency of endocrine abnormalities in sexually mature men with mild hypospadias. For this purpose we evaluated 16 men 22 to 52 years old with mild hypospadias. All patients had a urethral meatus distal to the penoscrotal junction. Serum concentrations of luteinizing hormone, follicle-stimulating hormone and testosterone were measured in all subjects. Dihydrotestosterone and testosterone precursors also were determined in men who had abnormally elevated levels of luteinizing hormone. The level of serum luteinizing hormone in patients was significantly higher than that of normal men, whereas the levels of serum follicle-stimulating hormone and testosterone were similar to those of normal subjects. Of the 16 men with mild hypospadias 3 had abnormally elevated levels of gonadotropins: 2 had primary gonadal dysfunction (elevated luteinizing hormone and follicle-stimulating hormone with low or normal testosterone) and 1 had hormonal evidence of partial androgen insensitivity (elevated luteinizing hormone, normal follicle-stimulating hormone with high normal testosterone and dihydrotestosterone). These patients are rather unique, since they did not have other compromising factors to account for the gonadal failure. In summary, our data demonstrated the presence of endocrine dysfunction in men with mild hypospadias.

Linkage of congenital isolated adrenocorticotropic hormone deficiency to the corticotropin releasing hormone locus using simple sequence repeat polymorphisms

Genetic screening techniques using simple sequence repeat polymorphisms were applied to investigate the molecular nature of congenital isolated adrenocorticotropic hormone (ACTH) deficiency. We hypothesize that this rare cause of hypocortisolism shared by a brother and sister with two unaffected sibs and unaffected parents is inherited as an autosomal recessive single gene mutation. Genes involved in the hypothalamic-pituitary axis controlling cortisol sufficiency were investigated for a causal role in this disorder. Southern blotting showed no detectable mutations of the gene encoding pro-opiomelanocortin (POMC), the ACTH precursor. Other candidate genes subsequently considered were those encoding neuroendocrine convertase-1, and neuroendocrine convertase-2 (NEC-1, NEC-2), and corticotropin releasing hormone (CRH). Tests for linkage were performed using polymorphic di- and tetranucleotide simple sequence repeat markers flanking the reported map locations for POMC, NEC-1, NEC-2, and CRH. The chromosomal haplotypes determined by the markers flanking the loci for POMC, NEC-1, and NEC-2 were not compatible with linkage. However, 22 individual markers defining the chromosomal haplotypes flanking CRH were compatible with linkage of the disorder to the immediate area of this gene on chromosome 8. Based on these data, we hypothesize that the ACTH deficiency in this family is due to an abnormality of CRH gene structure or expression. These results illustrate the useful application of high density genetic maps constructed with simple sequence repeat markers for inclusion/exclusion studies of candidate genes in even very small nuclear families segregating for unusual phenotypes.

Prevalence of polymorphic 21-hydroxylase gene (CA21HB) mutations in salt-losing congenital adrenal hyperplasia

Using genomic restriction analysis of 14 unrelated patients with salt-losing congenital adrenal hyperplasia, we identified three different CA21HB mutation patterns: no detectable restriction fragment abnormalities (16/28 haplotypes), deletion of the active CA21HB gene (9/28), and apparent conversion of the active CA21HB gene to the pseudogene CA21HA (3/28). CA21HB gene deletion was associated with HLA-Bw47 in 6 haplotypes and with absent C4B expression in 7. A variety of HLA and C4 types was associated with the other mutations. Apparent conversion of CA21HB to CA21HA was identified by the disparity between the intensity ratios for the major TaqI and BglII hybridization fragments.