Newborn screening for 21-hydroxylase deficiency: results of CYP21 molecular genetic analysis

Blood samples for plasma steroid hormone determinations and molecular genotype analysis of the 21-hydroxylase gene (CYP21) were obtained from 15 infants identified through a voluntary newborn screening program. Mutations were identified on both CYP21 alleles in 12 (80%) of 15 infants; all had confirmatory plasma 17-hydroxyprogesterone concentrations > 3500 ng/dl. No patient was found to carry mutations associated with late-onset 21-hydroxylase deficiency. Newborn screening hastened diagnosis in eight infants.

Evidence for a heterozygote advantage in congenital adrenal hyperplasia due to 21-hydroxylase deficiency

21-Hydroxylase deficiency is one of the most common inherited disorders, with carrier frequencies of approximately 10% in all world populations studied to date. The high prevalence of the mutant gene is probably due to a flanking pseudogene serving as a reservoir for mutations. Despite the potential for a high rate of de novo mutations, a founder effect for specific gene conversions is observed in most populations. We hypothesized that there was a survival advantage to 21-hydroxylase heterozygotes, and here we report endocrinological and molecular investigations to test this hypothesis. We defined 28 carriers and 22 mutation-negative controls by molecular genotyping and determined ACTH-stimulated adrenal hormone responses. We found significantly elevated cortisol responses in the carriers compared to controls (30 min cortisol levels: normal, 24.2 +/- 4.6 micrograms/dL; carrier, 28.1 +/- 4.2 micrograms/dL; P < 0.005). Cortisol has a crucial role in maintaining homeostasis, influencing differentiation, suppressing inflammation, and effecting cross-talk among the immune, nervous, and endocrine systems. The brisk cortisol response we have documented in carriers of 21-hydroxylase may enable a rapid return to homeostasis in response to infectious, inflammatory, or other environmental stresses and may protect from inappropriate immune responses, such as autoimmune diseases.

Time to conception after orchidopexy: evidence for subfertility?

OBJECTIVE

To determine whether time to conception is increased among men who were formerly bilaterally or unilaterally cryptorchid compared with a group of matched control men.

DESIGN

Retrospective cohort study.

SETTING

Human volunteers in an academic research environment.

PATIENT(S)

Men who underwent orchidopexy between 1955 and 1971 at the Children's Hospital of Pittsburgh (n = 547) and a group of matched control men (n = 463) were surveyed by questionnaire.

RESULT(S)

Of the men who attempted paternity, the mean time to conception for the bilateral cases, unilateral cases, and control men was 33.90, 11.11, and 8.78 months, respectively. Kaplan-Meier survival analysis showed a significantly longer time to conception among bilateral cases compared with unilateral cases and controls, but not between unilateral cases and control men. Adjustment for confounders and covariates using a Cox Proportional Hazards model showed that former bilaterally cryptorchid men were 68% (95% CI = 55% to 81%) less likely than former unilaterally cryptorchid men or controls to conceive per month of unprotected intercourse.

CONCLUSION(S)

Time to conception was increased among former bilaterally cryptorchid men compared with both former unilaterally cryptorchid and control men. However, there were no significant differences in time to conception between the unilateral cryptorchid men and the control men.

Paternity after bilateral cryptorchidism. A controlled study

OBJECTIVE

To compare paternity among men with former bilateral cryptorchidism (referred to as the bilateral group) with a group of men with former unilateral cryptorchidism (referred to as the unilateral group) and a control group.

DESIGN

Epidemiologic survey of study cohort.

SETTING

Large urban pediatric hospital.

SUBJECTS

Men with former bilateral and unilateral cryptorchidism who underwent orchiopexy between 1955 and 1971 at the Children's Hospital of Pittsburgh, Pittsburgh, Pa, and a group of control men have been surveyed by questionnaire concerning paternity and factors related to paternity.

MAIN OUTCOME MEASURE

Paternity.

RESULTS

Among the married men who had bilateral cryptorchidism, 50% had fathered children, compared with 76% in the control group and 74% in the unilateral group. Data were similar when the men who were cohabitating were included with the married men. When men who had married and had attempted paternity were evaluated, 62% of the men in the bilateral group had been able to father children compared with 94% of the control group and 89% of the men in the unilateral group. No relationship was noted between the age of orchiopexy or lifestyle factors and paternity. Paternity among all groups was related to female-related infertility factors and to the presence of varicoceles.

CONCLUSIONS

Paternity was compromised after bilateral cryptorchidism when compared with men with former unilateral cryptorchidism and a control group. Among the bilateral group, infertility is about 3.5 times as frequent than the unilateral group and more than 6 times as frequent among the control group. No correlation was found between age of orchiopexy and paternity for either group.

Paternity after unilateral cryptorchidism: a controlled study

OBJECTIVE

To determine if paternity is decreased among formerly unilateral cryptorchid men compared with a control group of men.

SUBJECTS AND METHODS

Formerly unilateral cryptorchid men who had orchiopexy between 1955 and 1971 at the Children's Hospital of Pittsburgh and a group of control men have had their medical records reviewed and have been surveyed by questionnaire.

RESULTS

Among the men who had ever married and had attempted paternity, significantly more of the unilateral cryptorchid men had been unable to father children (10.5%) than among the control group (5.4%). No difference was found when the groups were compared for the duration of regular intercourse without contraception to conception of their first child. There was no relationship between the age of orchiopexy or lifestyle factors and paternity or between the age of orchiopexy and months of regular unprotected intercourse to conception. Paternity among both groups was related to female-related infertility factors and to the presence of varicoceles.

CONCLUSION

When compared with a control group, paternity was compromised after unilateral cryptorchidism. Infertility is about twice as frequent among the unilateral group. There was no evidence of subfertility requiring a longer exposure of regular intercourse without contraception among the fertile subgroup. No correlation was found between age of orchiopexy and paternity.

Treatment of central precocious puberty: comparison of urinary gonadotropin excretion and gonadotropin-releasing hormone (GnRH) stimulation tests in monitoring GnRH analog therapy

GnRH analogs (GnRH-a) have proven to be efficacious and have become the standard treatment for central precocious puberty (CPP). To confirm the diagnosis of CPP and to monitor the adequacy of hvpothalamic-pituitary-gonadal (HPG) axis suppression, GnRH stimulation testing has been essential. To determine whether 24-h urinary gonadotropin excretion could adequately assess HPG axis suppression, we compared the results of simultaneous GnRH stimulation tests and 24-h urinary gonadotropin determinations in 18 girls with CPP who were receiving GnRH-a therapy (leuprolide acetate, Depot-Lupron, TAP Pharmaceuticals). HPG axis suppression was defined as the absence of significant LH and FSH responses to GnRH stimulation. Simultaneous GnRH stimulation tests and urinary gonadotropin determinations had a concordance rate of 68% (42 of 62). The sensitivity and specificity of urinary LH determinations to detect inadequate HPG suppression were 75% and 64%, respectively. For urinary FSH determinations, the sensitivity and specificity were 90% and 28%, respectively. Hence, single timed urine collections lacked the sensitivity and specificity to assess HPG axis suppression and, thus, cannot replace GnRH stimulation tests for monitoring the adequacy of the GnRH-a dose.

Salivary testosterone levels in male adolescents with cystic fibrosis

PURPOSE

Salivary testosterone concentrations have been used for monitoring testosterone levels in male adolescents and have been found to correlate closely with serum values. Data are lacking on such measurements in male adolescents with cystic fibrosis (CF), in which salivary gland abnormalities are commonly seen. Delayed sexual maturation occurs in many patients with CF, particularly those with severe disease. We examined the usefulness of salivary testosterone collection and measurement in male adolescents with CF.

METHODS

Forty boys with CF and 35 healthy control boys participated in the study. All boys were Tanner staged and had serum and salivary testosterone concentrations measured. Testosterone assays were performed using standard radioimmunoassay techniques.

RESULTS

The boys with CF were slight older, lighter in body weight, and shorter. Serum and salivary testosterone concentrations were lower in the CF group than in the control group. A significant correlation was found between serum and salivary testosterone levels for boys with CF (r = .84) and for the control boys (r = .86). Mean salivary testosterone increased as age progressed and as Tanner stage advanced.

CONCLUSIONS

These results demonstrate that salivary testosterone measurements correlate well with serum values in male adolescents with CF and can be used in the monitoring of pubertal status.

Progressive virilization of a pubertal phenotypic female: 17 beta-hydroxysteroid dehydrogenase deficiency

17 beta-Hydroxysteroid dehydrogenase deficiency is an uncommon inherited disorder characterized by genital ambiguity and progressive pubertal virilization. We describe the clinical and biochemical features in a 13-year-old 46, XY individual who presented with progressive pubertal virilization.

Who is a carrier? Detection of unsuspected mutations in 21-hydroxylase deficiency

Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is a common autosomal-recessive disorder. During our routine genotyping of affected individuals and their relatives using allele-specific oligonucleotide hybridization and single-strand conformational polymorphism analysis, we identified two families each segregating three mutations. In both families, a mutation known to be associated with 21-hydroxylase deficiency was identified in healthy individuals but was not detected in the propositus. The propositus in family 1 was shown to be a homozygous carrier for G at nucleotide 655, which alters the splice acceptor site at exon 3. The propositus in family 2 carried the same splicing mutation on the maternal allele and a gene deletion/conversion on the paternal allele. In both families, other clinically unaffected relatives carried the Q318X mutation in exon 8. If molecular diagnostic studies had been limited to the mutation carried by the propositi, relatives would have been misinformed regarding their status as carriers or mildly affected individuals. The findings in these two families emphasize the high frequency of alleles causing 21-hydroxylase deficiency in the population.

Ultradian rhythms in performance on tests of specialized cognitive function

Performance on cognitive tasks cycled at ultradian frequencies for 24 males over a test period of eight hours. The verbal task of written word production cycled at 80 minutes; the spatial task of locating points in space cycled at 96 minutes. Multiple cycles were seen for a perceptual speed task that factor loads on both the verbal and spatial task. Replication of the results for the first 12 and second 12 subjects demonstrated their robustness. The verbal and spatial tasks were chosen to reflect specialized functions of the left and right cerebral hemispheres, respectively. Accordingly, the results are interpreted as evidence that specialized task performances are associated with independent neurochemical systems. In addition, blood samples were taken at task performance to assess cyclicity of hormone levels. Luteinizing hormone had a period of 120 minutes, testosterone and cortisol were inconsistent and none seemed to be related to the cognitive tasks. However when subjects were divided according to a winter or summer testing schedule, the spatial periodicity was absent for the summer group and the verbal periodicity was absent for the winter peak.

Consequence of cryptorchidism: relationship to etiology and treatment

Increased risk of infertility and testicular tumors after cryptorchidism is the basis for treatment. Over the past few decades the recommended age of therapy has become younger and younger, so that currently therapy is recommended before 2 years of age and as early as 6 months. Evidence indicates that treatment before 10 years of age reduces the incidence of testicular tumors among men who formerly had unilateral cryptorchidism to that of men without a history of cryptorchidism. However, the effect of the age of treatment among the bilateral group is unknown. Infertility after bilateral cryptorchidism is about six times greater than that of the general population, affecting about half of patients; it appears to be only two times greater among the unilateral group, affecting about 10% of patients. To date no effect of age of therapy has been demonstrated, although current studies have not been able to consider the underlying cause of the cryptorchidism. Data are not yet available to determine whether pretreatment testicular location or size is related to subsequent fertility. The current recommendation for treatment within the first 2 years of life is based on the progressive degeneration of germ cells within the persistently cryptorchid testis after the first year of life. This recommendation should stand, even though some testes may be irretrievably damaged before such early therapy, and others may suffer minimal or no detrimental effect after delayed treatment. Future information may identify specific causes of cryptorchidism and, hence, determination of which patients will benefit from early therapy.

Normal ranges for immunochemiluminometric gonadotropin assays

OBJECTIVE

We sought to establish normative data for spontaneous and gonadotropin-releasing hormone (GnRH)-stimulated serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels measured by new immunochemiluminometric assays (ICMA) in children and adolescents.

METHODS

Random serum samples were obtained from 375 normal subjects (0.1 to 17.7 years, 230 female subjects). Intravenous GnRH stimulation tests were performed in 41 normal subjects (4.8 to 18 years, 20 female subjects). Normal ranges were calculated by age and Tanner stage. Immunochemiluminometric assays of LH and FSH concentrations were compared with levels obtained by a sensitive immunofluorometric assay and a less sensitive radioimmunoassay.

RESULTS

Random gonadotropin concentrations in normal children followed the pattern of transient elevation in infancy, low but measurable prepubertal levels, and markedly increased values at puberty. Spontaneous LH levels were higher in male infants but were not statistically different in boys and girls after infancy. Mean prepubertal LH was 0.04 +/- 0.04 IU/L (n = 66), rising 100-fold during puberty. Spontaneous FSH levels were much higher than LH values, were higher in female infants, and rose threefold at puberty. Peak GnRH-stimulated LH was identical in prepubertal boys and girls (1.8 +/- 1.3 IU/L, n = 17) and increased 20-fold at puberty. Mean peak GnRH-stimulated FSH was highest in prepubertal female subjects. Luteinizing hormone values measured by ICMA and immunofluorometric assay were highly correlated, but radioimmunoassay levels diverged markedly from ICMA levels at lower concentrations. Because absolute levels were higher, FSH values correlated adequately in the three assays throughout the normal physiologic range.

CONCLUSIONS

Measurement of LH by ICMA is much more sensitive than older assay methods. Spontaneous LH can be accurately measured by ICMA to the very low levels present in normal prepubertal children, providing a potentially important biochemical discriminator of pubertal status. An ICMA GnRH-stimulated LH level greater than 5 IU/L is suggestive of maturing gonadotropin secretion. The ICMA LH assays provide significant enhancement in sensitivity; these assays should be used when levels may be low, and by their accuracy may reduce the time and expense of testing procedures.

Spontaneous serum gonadotropin concentrations in the evaluation of precocious puberty

OBJECTIVE

We assessed the utility of spontaneous and gonadotropin-releasing hormone (GnRH)-stimulated serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels measured by new immunochemiluminometric assays in the evaluation and monitoring of precocious puberty.

METHODS

We evaluated serum gonadotropin values from intravenous GnRH stimulation tests in 49 girls with clinical signs suggesting central precocious puberty (CPP). Because GnRH-stimulated LH has been considered the standard for diagnosing CPP, we used it as the basis for comparison with GnRH-stimulated FSH levels and spontaneous LH and FSH measured by immunochemiluminometric assay.

RESULTS

Twenty-six patients had a peak serum LH value above the +2 SD threshold for normal prepubertal female subjects (LH > 5 IU/L). The GnRH-stimulated FSH values had a narrow range and did not discriminate patients with CPP. In contrast, elevations in spontaneous LH and FSH were found to be specific for CPP. Spontaneous LH levels correlated strongly with peak stimulated LH levels in subjects with precocious puberty (r = 0.79) or in control subjects (r = 0.93, both p (0.0001). Spontaneous LH levels in excess of 0.1 IU/L detected true puberty with 94% sensitivity and 88% specificity. Random LH levels in excess of 0.3 IU/L had 100% specificity for CPP.

CONCLUSIONS

The GnRH-stimulated FSH levels do not adequately differentiate children with and without CPP and have limited utility in the evaluation of precocious puberty. Spontaneous FSH levels are elevated in CPP with fair sensitivity and marked specificity. Elevated random LH, measured by third-generation assay such as immunochemiluminometric assay, is strongly correlated with and highly predictive of elevated peak GnRH-stimulated LH, and is a useful screening tool for CPP.

Paternity after cryptorchidism: lack of correlation with age at orchidopexy

OBJECTIVE

To determine whether paternity is decreased among men who were formerly unilaterally or bilaterally cryptorchid and to ascertain whether paternity is related to their age at orchidopexy.

SUBJECTS AND METHODS

Men who underwent orchidopexy between 1955 and 1969 at the Children's Hospital of Pittsburgh (363) and a group of age-matched control men (336) were surveyed by questionnaire and their medical records reviewed.

RESULTS

Of the married men, significantly more of the unilateral cryptorchid (75%) and control (76%) groups had fathered children than had the bilateral cryptorchid group (P < 0.005). Furthermore, when the groups were compared during the period of regular intercourse with no contraception until conception of their first child, the bilateral group had relatively fewer conceptions during the first year and more after the first year. When the unilateral and bilateral groups were analysed separately, there was no relationship between either age at orchidopexy and paternity or between the age at orchidopexy and the duration of regular unprotected intercourse before conception.

CONCLUSIONS

Compared with a control group, paternity was compromised after bilateral, but not unilateral, cryptorchidism. Age at orchidopexy was not correlated with paternity.