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Biomedical subjects

P W Speiser

Publications and source records attributed to P W Speiser.

At least 19 recordsLinked to original sources
PubMed2006

Reproductive outcome of women with 21-hydroxylase-deficient nonclassic adrenal hyperplasia.

CONTEXT: Because many women with 21-hydroxylase (21-OH)-deficient nonclassic adrenal hyperplasia (NCAH) carry at least one allele affected by a severe mutation of CYP21, they are at risk for giving birth to infants with classic adrenal hyperplasia (CAH). OBJECTIVE: Our objective was to determine the frequency of CAH and NCAH infants born to mothers with 21-OH-deficient NCAH. DESIGN AND SETTING: We conducted an international multicenter retrospective/prospective study. PATIENTS AND METHODS: The outcome of 203 pregnancies among 101 women with 21-OH-deficient NCAH was reviewed. The diagnosis of 21-OH-deficient NCAH was established by a basal or post-ACTH-stimulation 17-hydroxyprogesterone level of more than 10 ng/ml (30.3 nmol/liter). When possible, genotype analyses were performed to confirm CAH or NCAH in the offspring. RESULTS: Of the 203 pregnancies, 138 (68%) occurred before the mother's diagnosis of NCAH and 65 (32%) after the diagnosis. Spontaneous miscarriages occurred in 35 of 138 pregnancies (25.4%) before the maternal diagnosis of NCAH, and in only four of 65 pregnancies (6.2%) after the diagnosis (P < 0.002). Four (2.5%; 95% confidence interval, 0.7-6.2%) of the 162 live births were diagnosed with CAH. To date, 24 (14.8%; 95% confidence interval, 9.0-20.6%) children, 13 girls and 11 boys, have been diagnosed with NCAH. The distribution of NCAH children and their mothers varied significantly by ethnicity (P < 0.0001, for both). CONCLUSIONS: The risk of a mother with 21-OH-deficient NCAH for giving birth to a child affected with CAH is 2.5%; at least 14.8% of children born to these mothers have NCAH.

Adrenal Hyperplasia, Congenital↗
PubMed2001

Congenital adrenal hyperplasia: transition from chil dhood to adulthood.

Congenital adrenal hyperplasia (CAH) is a group of disorders caused by inborn errors of steroid metabolism. The most common form owing to 21-hydroxylase deficiency (CAH-21OHD) is present in about 1:10,000- 1:15,000 live births worldwide. In its classic salt-wasting form (-66-75% of cases) patients may suffer potentially lethal adrenal insufficiency. Non-salt-wasting forms of CAH-21 OHD are recognized by genital ambiguity in affected females, and by signs of androgen excess in later childhood in males. Non-classic CAH-21 OHD may be detected in up to 1-3% of certain populations, and is often mistaken for idiopathic precocious pubarche in children or polycystic ovary syndrome in young women. This chapter will address issues relating to transition of CAH care from the pediatric to the adult endocrinologist.

Adolescent↗
PubMed2001

Congenital adrenal hyperplasia owing to 21-hydroxylase deficiency.

Congenital adrenal hyperplasia (CAH) owing to 21-hydroxylase deficiency is the most common cause of genital ambiguity in the newborn and is present in about 1 in 15,000 live births worldwide. The disease is further characterized in its classic salt-wasting form (approximately 75% of cases) by potentially lethal adrenal insufficiency. A non-salt-wasting form of classic CAH with 21-hydroxylase deficiency is also recognized by genital ambiguity in affected females and by signs of androgen excess in later childhood in males. Nonclassic CAH with 21-hydroxylase deficiency may be detected in 1% to 3% of populations and is often mistaken for idiopathic precocious pubarche in children or polycystic ovary syndrome in young women. This article presents an overview of clinical and genetic aspects of the various forms of CAH with 21-hydroxylase deficiency.

Adrenal Cortex↗
PubMed2001

Molecular diagnosis of CYP21 mutations in congenital adrenal hyperplasia: implications for genetic counseling.

Congenital adrenal hyperplasia (CAH) is an inherited disorder of steroid biosynthesis most often attributable to mutations in CYP21 (also termed CYP21A2) encoding the active steroid 21-hydroxylase enzyme. This review focuses on clinical and genetic aspects of CAH, and updates the reader on current methodology and applications for molecular genetic diagnosis. Genotyping patients with CAH has revealed > 50 mutations within CYP21, yet only 10 mutations account for approximately 95% of affected alleles. Many CYP21 mutations are gene conversions arising via transfer of gene sequences between the non-functional CYP21 pseudogene and CYP21. Phenotype is generally well-correlated with genotype. Historically, CAH has been divided into 3 types of disease: classic salt-wasting, classic simple virilizing (non-salt-wasting), and nonclassic. Recent findings support the notion that rather than discrete phenotypic categories, CAH is better represented as a continuum of phenotypes, from severe to mild. Molecular genetic diagnosis is most effectively employed now in prenatal diagnosis of classic CAH. As newborn screening for CAH becomes more widespread, genotyping may be implemented to resolve diagnostic difficulties encountered with hormonal testing. As automated methods of DNA diagnosis such as microarrays or gene chips are refined, it is likely that genetic screening will become less expensive and more readily available. The clinician should be aware of the potential for both false negatives and false positives with PCR-based gene screening. In short, whereas molecular genetic diagnosis is a valuable tool, it cannot replace clinical acumen and hormonal assays.

Adrenal Hyperplasia, Congenital↗
PubMed2000

Distinct missense mutations of the FGFR3 lys650 codon modulate receptor kinase activation and the severity of the skeletal dysplasia phenotype.

The fibroblast growth factor-receptor 3 (FGFR3) Lys650 codon is located within a critical region of the tyrosine kinase-domain activation loop. Two missense mutations in this codon are known to result in strong constitutive activation of the FGFR3 tyrosine kinase and cause three different skeletal dysplasia syndromes-thanatophoric dysplasia type II (TD2) (A1948G [Lys650Glu]) and SADDAN (severe achondroplasia with developmental delay and acanthosis nigricans) syndrome and thanatophoric dysplasia type I (TD1) (both due to A1949T [Lys650Met]). Other mutations within the FGFR3 tyrosine kinase domain (e.g., C1620A or C1620G [both resulting in Asn540Lys]) are known to cause hypochondroplasia, a relatively common but milder skeletal dysplasia. In 90 individuals with suspected clinical diagnoses of hypochondroplasia who do not have Asn540Lys mutations, we screened for mutations, in FGFR3 exon 15, that would disrupt a unique BbsI restriction site that includes the Lys650 codon. We report here the discovery of three novel mutations (G1950T and G1950C [both resulting in Lys650Asn] and A1948C [Lys650Gln]) occurring in six individuals from five families. Several physical and radiological features of these individuals were significantly milder than those in individuals with the Asn540Lys mutations. The Lys650Asn/Gln mutations result in constitutive activation of the FGFR3 tyrosine kinase but to a lesser degree than that observed with the Lys540Glu and Lys650Met mutations. These results demonstrate that different amino acid substitutions at the FGFR3 Lys650 codon can result in several different skeletal dysplasia phenotypes.

Adolescent↗
PubMed2000

A multicenter study of women with nonclassical congenital adrenal hyperplasia: relationship between genotype and phenotype.

Characteristic presentation of nonclassical adrenal hyperplasia (NCAH) due to 21-hydroxylase deficiency was compared between women carrying a severe and a mild CYP21 mutation (Group 1, N = 26) versus homozygotes for mild mutations (Group 2, N = 8). The diagnosis was based on elevated ACTH-stimulated 17OH-progesterone (17OHP). Genotyping for 10 mutations was performed by PCR-based techniques. Jewish patients predominated among Group 2 (25% vs 11.5% in Group 1); however, 85% of all patients were non-Jewish Caucasians. Average age of presentation was 23-25 years, and did not differ between groups. Hirsutism, and to a lesser extent oligomenorrhea and acne, were more prevalent among Group 1 women. There was a trend to higher basal 17OHP among Group 1 patients (mean +/- SEM; 1354+/-323 vs 714+/-129 ng/dl, P< or =0.25). The lack of significant difference was perhaps due to the relatively few homozygotes for 2 mild mutations (24%). V281L was carried on approximately 48% of all alleles, and about 16% carried either P30L or P453S. Approximately 38% of alleles and 77% of patients carried a classic mutation. These data have important implications for genetic counseling. In summary, we describe differences in clinical, hormonal, and genetic characteristics among a multiethnic group of females with NCAH.

17-alpha-Hydroxyprogesterone↗
PubMed2000

21-Hydroxylase-deficient nonclassic adrenal hyperplasia is a progressive disorder: a multicenter study.

OBJECTIVE: Our aim was to determine whether the clinical features of 21-hydroxylase-deficient nonclassic adrenal hyperplasia are correlated with either age at symptom onset or age at presentation, or both, and with the degree of adrenocortical abnormality. STUDY DESIGN: In a multicenter cohort design 220 women with nonclassic adrenal hyperplasia, with a basal or adrenocorticotropic hormone-stimulated 17-hydroxyprogesterone level >30.3 nmol/L, were studied, either prospectively (n = 39) or retrospectively (n = 181). Patients were stratified by age of presentation into 5 groups: (1) <10 years (n = 25), (2) 10 to 19 years (n = 64), (3) 20 to 29 years (n = 83), (4) 30 to 39 years (n = 30), and (5) 40 to 49 years (n = 16). Two patients >50 years old were excluded from the analysis because of age. RESULTS: Ninety-two percent of patients <10 years old had premature pubarche at presentation, whereas clitoromegaly and acne were each present in only 20% of these younger subjects. With only patients > or =10 years old considered, presenting clinical features included hirsutism (59%), oligomenorrhea (54%), acne (33%), infertility (13%), clitoromegaly (10%), alopecia (8%), primary amenorrhea (4%), and premature pubarche (4%). Among the patients >/=10 years old, the prevalence but not the degree of hirsutism increased significantly with age. Basal levels of 17-hydroxyprogesterone in adolescents were significantly higher than the levels found either in children (<10 years old) or women 40 to 49 years old (P <.01 and P <.03, respectively), although no difference was noted in the stimulated 17-hydroxyprogesterone levels between age groups. The adrenocorticotropic hormone-stimulated levels but not the basal levels of 17-hydroxyprogesterone were significantly higher in patients with clitoromegaly than in women without clitoromegaly. Alternatively, there were no differences in either basal or stimulated 17-hydroxyprogesterone levels between patients with and those without hirsutism, acne, or alopecia. CONCLUSION: In children <10 years old the most common presenting complaint was premature pubarche, whereas hirsutism and oligomenorrhea were more common in older patients. The prevalence of hirsutism increased with age, suggesting the progressive nature of nonclassic adrenal hyperplasia. Furthermore, the adrenocorticotropic hormone-stimulated levels of 17-hydroxyprogesterone were higher in patients with clitoromegaly, which suggests that the degree of adrenocortical dysfunction in nonclassic adrenal hyperplasia determines, at least in part, the clinical presentation.

17-alpha-Hydroxyprogesterone↗
PubMed2000

Congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

More than 90% of cases of congenital adrenal hyperplasia (CAH, the inherited inability to synthesize cortisol) are caused by 21-hydroxylase deficiency. Females with severe, classic 21-hydroxylase deficiency are exposed to excess androgens prenatally and are born with virilized external genitalia. Most patients cannot synthesize sufficient aldosterone to maintain sodium balance and may develop potentially fatal "salt wasting" crises if not treated. The disease is caused by mutations in the CYP21 gene encoding the steroid 21-hydroxylase enzyme. More than 90% of these mutations result from intergenic recombinations between CYP21 and the closely linked CYP21P pseudogene. Approximately 20% are gene deletions due to unequal crossing over during meiosis, whereas the remainder are gene conversions--transfers to CYP21 of deleterious mutations normally present in CYP21P. The degree to which each mutation compromises enzymatic activity is strongly correlated with the clinical severity of the disease in patients carrying it. Prenatal diagnosis by direct mutation detection permits prenatal treatment of affected females to minimize genital virilization. Neonatal screening by hormonal methods identifies affected children before salt wasting crises develop, reducing mortality from this condition. Glucocorticoid and mineralocorticoid replacement are the mainstays of treatment, but more rational dosing and additional therapies are being developed.

Adrenal Cortex Hormones↗
PubMed2000

Ovarian hyperthecosis in the setting of portal hypertension.

Hepatocellular dysfunction and perturbed portal hemodynamics alter steroid metabolism. Men with liver disease have gynecomastia, although women similarly affected rarely show virilization. We report a 10-yr-old girl with portal hypertension and shunting associated with precocious puberty and ovarian hyperandrogenism. This was one of premature twin girls; neither had clitoromegaly or genital ambiguity. In one child, neonatal respiratory problems led to umbilical vein catheterization with subsequent development of portal hypertension. Pubic hair was first noted at age 6 yr, breasts at 7 yr, and severe acne and clitoromegaly at 10 yr. Baseline sex hormones were elevated: androstenedione (A), 413 ng/dL; testosterone (T), 226 ng/dL; and estradiol (E2), 160 pg/mL. Liver transaminases were within the normal range, however, the coagulation profile was mildly abnormal. Cosyntropin adrenal stimulation revealed no steroidogenic defect. Dexamethasone suppression reduced A and T slightly. LH-releasing hormone stimulation produced a pubertal rise in LH and FSH. Pelvic sonography showed a large right ovary with numerous follicles. Surgical exploration revealed symmetrically enlarged ovaries with dense capsules. Histology of ovarian wedge resections showed hyperthecosis; immunohistochemistry showed stromal cells expressing steroidogenic enzymes and proteins. One month postoperatively, A and T were unchanged from baseline, whereas E2 decreased to 56 pg/mL. A single dose of depot leuprolide acetate significantly reduced T. Subsequent treatment with oral contraceptives reduced T to 50 ng/dL, and cyclical menses occurred. We conclude that precocious puberty and ovarian hyperthecosis were induced in this young girl by elevated circulating levels of sex hormones, a consequence of portasystemic shunting and impaired hepatic steroid metabolism.

Androstenedione↗
PubMed1999

Regulation of HSD17B1 and SRD5A1 in lymphocytes.

We previously reported lymphocyte expression of genes encoding enzymes required for steroid metabolism; however, only 17beta-HSD and 5alpha-reductase showed significant enzyme activity. We now investigate regulation of lymphocyte expression for genes encoding 17beta-HSD and 5alpha-reductase. Cultured human T and B lymphoid cell lines and peripheral blood mononuclear cells were treated with known regulators of steroidogenic gene expression including forskolin, PMA, ionomycin, various steroids, interleukin (IL)-4, and IL-6. Treatment with 10 or 50 microM forskolin resulted in a 20-60% reduction of expression for HSD17B1 (encoding 17beta-HSD I) in T and B lymphoid cell lines and peripheral blood mononuclear cells, although such a change was not observed in the expression of SRD5A1 (encoding 5alpha-reductase I). No significant changes were found when cells were treated for 24 h with various concentrations of PMA or ionomycin. Incubation with 10(-9) to 10(-7) M androstenedione or estradiol increased expression of HSD17B1, while testosterone decreased the expression of this gene. SRD5A1 expression was increased in the presence of 5alpha-DHT although no consistent changes were observed when the cells were treated with testosterone. Other steroids, including dexamethasone, progesterone, and 6-hydroxypregnanolone, produced no effects on expression of either HSD17B1 or SRD5A1. Treatment with 0.1-10 ng/ml of IL-4 or IL-6 also did not effect significant changes in gene expression. These data implicate the involvement of the cAMP-protein kinase signal transduction pathway in regulating lymphocyte expression of HSD17B1. Furthermore, it appears that lymphocyte HSD17B1 and SRD5A1 are regulated to some extent by specific steroids.

17-Hydroxysteroid Dehydrogenases↗
PubMed1999

Genotyping of CYP21, linked chromosome 6p markers, and a sex-specific gene in neonatal screening for congenital adrenal hyperplasia.

We investigated the feasibility and diagnostic utility of genotyping 9 CYP21 mutations, linked chromosome 6p markers, and a dimorphic X-Y marker from neonatal screening samples. Blood-impregnated filter papers (Guthrie cards) from 603 randomly chosen New Zealand neonates were genotyped blind to 17-hydroxyprogesterone (17-OHP) levels. Another 50 samples from Swiss and North American infants with correlative hormonal data were also genotyped. DNA was extracted, and gene-specific PCR was performed. CYP21 PCR products were subjected to ligase detection reaction, simultaneously analyzing 9 CYP21 mutations; PCR products of other genes were subjected to direct gel analysis. CYP21 genotyping indicated a heterozygote rate of 2.8% for classic mutations (excluding CYP21 deletions), and 2.0% for nonclassic mutations in New Zealanders. Ten full-term affected neonates showed a wide range of 17-OHP levels (15-1400 nmol/L). Sick or preterm infants or infants screened on the first day of life with high 17-OHP proved genetically unaffected. Genetic linkage disequilibrium was found between two CYP21 mutations and chromosome 6p markers. Guthrie cards can be used to accurately genotype CYP21 and other relevant markers, potentially enhancing the specificity and sensitivity of congenital adrenal hyperplasia screening. CYP21 heterozygote frequency for classic mutations is higher than expected based on genotype compared with that predicted by hormonal newborn screening.

17-alpha-Hydroxyprogesterone↗
PubMed1999

Prenatal treatment of congenital adrenal hyperplasia.

PURPOSE: The relevant aspects of congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH-21), the single most common cause of female pseudohermaphroditism, are reviewed to understand the benefits and risks of prenatal intervention. Timely diagnosis is important, since infants with this condition may suffer adrenal insufficiency which carries a high mortality rate. MATERIALS AND METHODS: Infants suspected of having CAH-21 should undergo radioimmunoassay of serum 17-hydroxyprogesterone, karyotype and pelvic/abdominal ultrasound at a minimum. Treatment with glucocorticoid and mineralocorticoid supplements should be instituted immediately. Surgical correction of genitourinary tract anomalies should be performed by a pediatric urologist experienced in this area. RESULTS: Proper postnatal medical and surgical management of CAH-21 will allow the patient to thrive. Many women with classic CAH-21 have now conceived and delivered healthy children. Prenatal diagnosis, now most often done by molecular genetic techniques, is feasible and often done in conjunction with prenatal treatment of the at risk mother. CONCLUSIONS: CAH-21 has been well characterized. The benefit of prenatal therapy is to ameliorate potentially genital ambiguity in affected female subjects. The risks of unnecessarily treating unaffected pregnancies, which now seem small, may not be fully elucidated for many years. Prenatal treatment must be done under careful, centralized and ideally long-term medical supervision.

Adrenal Hyperplasia, Congenital↗
PubMed1998

Prominent sex steroid metabolism in human lymphocytes.

Steroid metabolism was investigated in cultured human B-lymphoblastoid cells (B-LCL), and peripheral blood T and B cells. Gene expression was examined by reverse-transcription polymerase chain reaction amplification (RT-PCR). Appropriate sized transcripts were detected in both cultured and fresh peripheral lymphocytes for CYP11A, CYP17, HSD11L (11beta-hydroxysteroid dehydrogenase I), HSD17B1 (17beta-hydroxysteroid dehydrogenase type I) and SRD5A1 (5alpha-reductase I). B-LCL, but not T and B cells, expressed CYP11B. There was minimal expression of HSD3B1 and HSD3B2 (3beta-hydroxysteroid dehydrogenase I and II) in B-LCL and T cells. Transcripts for CYP19 and HSD11K were not detected. Corresponding enzymatic activity was detectable only for 17-hydroxysteroid dehydrogenase and 5alpha-reductase, respectively producing testosterone and 5alpha-dihydrotestosterone. Steroid identities were confirmed by gas chromatography/mass spectrometry (GC/MS). One metabolite thought to be deoxycorticosterone was identified by GC/MS as 6alpha-hydroxypregnanolone. It was concluded that sex hormone metabolism, including androgen synthesis, occurs in lymphocytes, and may modulate immune response.

Adult↗
PubMed1998

Study of a kindred with classic congenital adrenal hyperplasia: diagnostic challenge due to phenotypic variance.

We sought to determine the concordance of the phenotype and genotype in a kindred with classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency. The variation in phenotypic expression within this family underscores the difficulty of establishing the diagnosis in the absence of newborn screening, even with a heightened index of suspicion. Steroidogenic profiles were obtained for the three affected siblings. The available clinical history of the two affected aunts was retrieved. Genotyping was performed on several members of the kindred. Detailed sequencing of the entire CYP21 gene of two clinically dissimilar subjects in this family was undertaken to explore the possibility of other mutations or polymorphisms. PCR with ligase detection reaction analysis of CYP21 revealed that the affected family members III-2, III-3, III-4, II-3, and II-4, all were compound heterozygotes carrying the intron 2 point mutation known to interfere with splicing (nucleotide 656 A to G) and the exon 4 point mutation causing a nonconservative substitution of asparagine for isoleucine at codon 172 (I172N). Detailed sequencing of the gene was performed for the two most phenotypically dissimilar subjects. A single silent polymorphism was found in the third nucleotide for codon 248 in patient II-4, but not in patient III-4, and no additional mutations were found. Classic congenital adrenal hyperplasia remains a difficult diagnosis to make in the absence of newborn screening because of the variability of phenotypic expression. Likewise, the variable degree of genital ambiguity in affected females in this family serves to question universal advocacy of prenatal steroid treatment in pregnancies at risk for congenital adrenal hyperplasia. Extensive molecular exploration did not provide an explanation of the phenotypic heterogeneity and supports the possibility of influences other than the CYP21 gene for the observed divergence.

Adrenal Hyperplasia, Congenital↗
PubMed1997

Steroid 21-hydroxylase expression and activity in human lymphocytes.

Steroid 21-hydroxylase encoded by CYP21 is expressed in adrenal cortex. Mutations in CYP21 cause potentially lethal congenital adrenal hyperplasia (CAH). Earlier observations suggested alternative sources of 21-hydroxylase activity, although its genetic source remains unclear. We found a novel source of CYP21 expression in normal human cultured B lymphocytes. The quantity of 21-hydroxylase transcript was reduced in B cell lines of CAH subjects compared with that in normal B-lymphoblastoid cells. No CYP21 transcript was detected in lymphocytes from a CAH patient with homozygous CYP21 deletion. Cultured lymphoid cells, including those carrying homozygous CYP21 deletion, and peripheral blood leukocytes converted both 17-hydroxyprogesterone to 11-deoxycortisol and progesterone to deoxycorticosterone. We conclude that lymphocytes express CYP21, but also possess a 21-hydroxylase distinct from CYP21. Activity of this isozyme may partially compensate for severe adrenal 21-hydroxylase deficiency.

Adrenal Hyperplasia, Congenital↗
PubMed1997

Expression of myogenic regulatory factors in normal and dystrophic mice: effects of IGF-1 treatment.

Myogenic regulatory factors (MRFs) promote differentiation of muscle cells from fibroblasts and are induced by insulin-like growth factor I (IGF-1). Prior studies have shown synthesis of new muscle protein and improved muscle morphology when mature dy mice with muscular dystrophy are treated with IGF-1. We investigated whether these salutary effects of IGF-1 might be attributable to stimulation of MRFs. Male dy (129ReJ) mice and controls (129J) were assigned to IGF-1 treatment (10 micrograms twice daily) or non-treatment at about 5 weeks of life and sacrificed 6 weeks later. RNA was extracted from skeletal muscles, reverse transcribed, and amplified by polymerase chain reaction (PCR) using primers specific for each MRF. Competitive PCR was performed to quantify MyoD expression in response to IGF-1 treatment. Transcripts for myf-5, MRF4, and myogenin were detected in both control and dy mouse muscles; no apparent differences were observed between treatment groups. Quantitative analysis of transcripts for MyoD indicated no significant basal differences between control and dy mice. There was, however, significantly higher MyoD expression in the dy group, and a trend toward significance in the control group, following IGF-1 treatment. These data suggest that IGF-1 exerts its in vivo effects in postembryonal muscle by stimulating MRFs.

Animals↗