Agneta Nordenskjöld

Nordic consensus on treatment of undescended testes

Aim: To reach consensus among specialists from the Nordic countries on the present state‐of‐the‐art in treatment of undescended testicles.

PHOX2B Genotype Allows for Prediction of Tumor Risk in Congenital Central Hypoventilation Syndrome

The Phox2b gene is necessary for autonomic nervous-system development. Phox2b-/- mice die in utero with absent autonomic nervous system circuits, since autonomic nervous system neurons either fail to form or degenerate. We first identified the Phox2b human ortholog, PHOX2B, as the gene underlying congenital central hypoventilation syndrome (CCHS, or Ondine curse), with an autosomal dominant mode of inheritance and de novo mutation at the first generation. We have subsequently shown that heterozygous mutations of PHOX2B may account for several combined or isolated disorders of autonomic nervous-system development--namely, tumors of the sympathetic nervous system (TSNS), such as neuroblastoma and late-onset central hypoventilation syndrome. Here, we report the clinical and molecular assessments of a cohort of 188 probands with CCHS, either isolated or associated with Hirschsprung disease and/or TSNS. The mutation-detection rate was 92.6% (174/188) in our series, and the most prevalent mutation was an in-frame duplication leading to an expansion of +5 to +13 alanines in the 20-alanine stretch at the carboxy terminal of the protein. Such findings suggest PHOX2B mutation screening as a simple and reliable tool for the diagnosis of CCHS, independent of the clinically variable phenotype. In addition, somatic mosaicism was detected in 4.5% of parents. Most interestingly, analysis of genotype-phenotype interactions strongly supports the contention that patients with CCHS who develop malignant TSNS will harbor either a missense or a frameshift heterozygous mutation of the PHOX2B gene. These data further highlight the link between congenital malformations and tumor predisposition when a master gene in development is mutated.

Gender Role Behavior, Sexuality, and Psychosocial Adaptation in Women with Congenital Adrenal Hyperplasia due to CYP21A2 Deficiency

CONTEXT Gender-atypical behavior has been described in young girls as well as in women with congenital adrenal hyperplasia (CAH) due to a CYP21A2 deficiency. OBJECTIVE The aim of the study was to assess health-related, psychosexual, and psychosocial parameters and correlate the results to CYP21A2 genotype. DESIGN AND PARTICIPANTS Sixty-two Swedish women with CAH and age-matched controls completed a 120-item questionnaire and a validated quality of life instrument [psychological general well-being (PGWB) formula] to identify psychosexual and psychosocial parameters. The patients were divided into four CYP21A2 genotype groups. RESULTS The women with CAH held more male-dominant occupations (30%) compared to controls (13%) (P = 0.04), especially those in the null genotype group (55%) (P = 0.006). They also reported a greater interest in rough sports (74%) compared to controls (50%) (P = 0.007). Eight women with CAH (14%) reported a prime interest in motor vehicles, compared to none of the controls (P = 0.002). Non-heterosexual orientation was reported by 19% of women with CAH (P = 0.005), 50% in the null genotype group (P = 0.0001), 30% in I2 splice (NS), and 5% in I172N (NS). PGWB total score did not differ between patients and controls. CONCLUSION We identified increased gender-atypical behavior in women with CAH that could be correlated to the CYP21A2 genotype. This speaks in favor of dose-dependent effects of prenatal androgens on the development of higher brain functions. The impact of the disease on upbringing and interpersonal relationships did not correlate with disease severity, indicating that other factors, such as coping strategies, are important for psychosocial adaptation. This illustrates the need for psychological support to parents and patients.

HEREDITY OF HYPOSPADIAS AND THE SIGNIFICANCE OF LOW BIRTH WEIGHT

PURPOSE We analyzed a large group of patients with hypospadias regarding familial aggregation, phenotype, twin rate and ethnic origin and assessed the correlation of low birth weight with hypospadias. MATERIALS AND METHODS We mailed questionnaires to 2,503 boys operated on for hypospadias in Sweden asking for additional cases of hypospadias in the family, the number of brothers in the nuclear family, and birth weight of the boys with hypospadias and their brothers. RESULTS Of the boys 7% reported 1 or more additional family members with hypospadias. The birth weight of the boys with hypospadias was significantly lower (p = 5 x 10-13) than the birth weight of their unaffected brothers. Phenotyping of 676 individuals revealed glandular hypospadias in 53%, penile forms in 39%, penoscrotal or perineal variants in 6% and cleaved prepuce as the only manifestation in 2%. There were 50% more twins than expected compared to the general population and established zygosity in 83% (67% monozygotic, 33% dizygotic). Non-Swedish ethnicity was noted in 22% of the subjects, a third of whom were from Middle Eastern countries. CONCLUSIONS We present data on heredity, birth weight, phenotype and ethnic origin in a large group of patients with hypospadias. The finding of additional members with hypospadias in 7% of the families supports the concept that genetic factors are involved in the pathogenesis. The strong association with low birth weight may be explained by genetic and environmental factors.

Fertility and pregnancy outcome in women with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

BACKGROUND Low pregnancy rate has been reported in women with congenital adrenal hyperplasia (CAH) and little information on pregnancy and children is known. METHODS In a Swedish study, 62 adult women with CAH, aged 18-63 years, and 62 age-matched controls were followed-up. Medical records, including those concerning pregnancies and deliveries, were examined and the 21-hydroxylase genotype of patients was noted. All women answered a questionnaire concerning sexual and reproductive health including health of the children. RESULTS Pregnancy and delivery rates were significantly lower in women with CAH (P < 0.001, P < 0.0056, respectively), and the severity of the 21-hydroxylase-mutation correlated with the reduced number of children born. More women with salt-wasting CAH were single and had not attempted pregnancy. Pregnancies were normal except for a significantly increased incidence of gestational diabetes in CAH patients (P < 0.0024). The children had normal birthweight and no malformations were observed. A later follow-up of the children showed a normal intellectual and social development. The sex ratio of the offspring differed significantly, with 25% boys in the CAH group compared with 56% among controls (P < 0.016). CAH women had more gynaecological morbidity during menopause. CONCLUSIONS Pregnancy and delivery rates are reduced in women with CAH mainly due to psychosocial reasons. The outcome of children did not differ from controls. The unexpected sex ratio in children born to mothers with CAH warrants further research.

HYPOSPADIAS IS RELATED TO BIRTH WEIGHT IN DISCORDANT MONOZYGOTIC TWINS

PURPOSE Hypospadias is a common urogenital malformation in boys. The etiology is unknown but genetic and environmental factors are involved. Because monozygotic twins have the same genetic constitution, we studied disease discordant twin pairs to evaluate environmental risk factors while controlling for genetic effects. MATERIALS AND METHODS We used questionnaires to identify 28 male twins discordant for hypospadias at 4 pediatric surgical clinics in Sweden. Using deoxyribonucleic acid fingerprinting, and histopathological examination of the placenta and fetal membranes 18 twin pairs were diagnosed as monozygotic. RESULTS In 16 of the 18 monozygotic pairs discordant for hypospadias the twin with the lowest birth weight has hypospadias. Mean difference in birth weight was 498 gm. (t = 3.8, p <0.01). CONCLUSIONS Environmental factors associated with low birth weight are involved in the etiology of hypospadias.

Common variants in DGKK are strongly associated with risk of hypospadias

Hypospadias is a common congenital malformation of the male external genitalia. We performed a genome-wide association study using pooled DNA from 436 individuals with hypospadias (cases) and 494 controls of European descent and selected the highest ranked SNPs for individual genotyping in the discovery sample, an additional Dutch sample of 133 cases and their parents, and a Swedish series of 266 cases and 402 controls. Individual genotyping of two SNPs (rs1934179 and rs7063116) in DGKK, encoding diacylglycerol kinase κ, produced compelling evidence for association with hypospadias in the discovery sample (allele-specific odds ratio (OR) = 2.5, P = 2.5 × 10−11 and OR = 2.3, P = 2.9 × 10−9, respectively) and in the Dutch (OR = 3.9, P = 2.4 × 10−5 and OR = 3.8, P = 3.4 × 10−5) and Swedish (OR = 2.5, P = 2.6 × 10−8 and OR = 2.2, P = 2.7 × 10−6) replication samples. Expression studies showed expression of DGKK in preputial tissue of cases and controls, which was lower in carriers of the risk allele of rs1934179 (P = 0.047). We propose DGKK as a major risk gene for hypospadias.

Maternal and Gestational Risk Factors for Hypospadias

Background An increase in the prevalence of hypospadias has been reported, but the environmental causes remain virtually unknown. Objectives Our goal was to assess the association between risk of hypospadias and indicators of placental function and endogenous hormone levels, exposure to exogenous hormones, maternal diet during pregnancy, and other environmental factors. Methods We conducted a case–control study in Sweden and Denmark from 2000 through 2005 using self-administered questionnaires completed by mothers of hypospadias cases and matched controls. The response rate was 88% and 81% among mothers of cases and controls, respectively. The analyses included 292 cases and 427 controls. Results A diet during pregnancy lacking both fish and meat was associated with a more than 4-fold increased risk of hypospadias [odds ratio (OR) = 4.6; 95% confidence interval (CI), 1.6–13.3]. Boys born to obese [body mass index (BMI) ≥ 30] women had a more than 2-fold increased risk of hypospadias (OR = 2.6; 95% CI, 1.2–5.7) compared with boys born to mothers with a normal weight (BMI = 20–24). Maternal hypertension during pregnancy and absence of maternal nausea increased a boy’s risk of hypospadias 2.0-fold (95% CI, 1.1–3.7) and 1.8-fold (95% CI, 1.2–2.8), respectively. Nausea in late pregnancy also appeared to be positively associated with hypospadias risk (OR = 7.6; 95% CI, 1.1–53). Conclusions A pregnancy diet lacking meat and fish appears to increase the risk of hypospadias in the offspring. Other risk associations were compatible with a role for placental insufficiency in the etiology of hypospadias.

Genome-wide association analyses identify variants in developmental genes associated with hypospadias

Hypospadias is a common congenital condition in boys in which the urethra opens on the underside of the penis. We performed a genome-wide association study on 1,006 surgery-confirmed hypospadias cases and 5,486 controls from Denmark. After replication genotyping of an additional 1,972 cases and 1,812 controls from Denmark, the Netherlands and Sweden, 18 genomic regions showed independent association with P < 5 × 10−8. Together, these loci explain 9% of the liability to developing this condition. Several of the identified regions harbor genes with key roles in embryonic development (including HOXA4, IRX5, IRX6 and EYA1). Subsequent pathway analysis with GRAIL and DEPICT provided additional insight into possible genetic mechanisms causing hypospadias.

Boys with Undescended Testes: Endocrine, Volumetric and Morphometric Studies on Testicular Function before and after Orchidopexy at Nine Months or Three Years of Age

CONTEXT A randomized controlled study was conducted comparing the outcome of surgery for congenital cryptorchidism at 9 months or 3 yr of age. OBJECTIVE The aim of the study was to investigate whether surgery at 9 months is more beneficial than at 3 yr and to identify early endocrine markers of importance for testicular development. PATIENTS AND METHODS A total of 213 biopsies were taken at orchidopexy, and the number of germ and Sertoli cells per 100 seminiferous cord cross-sections and the surface area of seminiferous tubules and interstitial tissue were analyzed. Inhibin B, FSH, LH, and testosterone were determined. Testicular volume was assessed by ultrasonography and by a ruler. RESULTS The number of germ and Sertoli cells and testicular volume at 9 months were significantly larger than at 3 yr. The intraabdominal testes showed the largest germ cell depletion at 3 yr. At both ages, testicular volume correlated to the number of germ and Sertoli cells. None of the hormones measured during the first 6 months of life (LH, FSH, testosterone, and inhibin B) could predict the number of germ or Sertoli cells at either 9 or 36 months of age, nor could hormone levels predict whether spontaneous descent would occur or not. CONCLUSION Morphometric and volumetric data show that orchidopexy at 9 months is more beneficial for testicular development than an operation at 3 yr of age. Testicular volume was furthermore shown to reflect germ cell numbers in early childhood, whereas endocrine parameters could not predict cellular structure of the testis or its spontaneous descent.