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Micropenis and the 5-Reductase-2 (SRD5A2) Gene: Mutation and V89L Polymorphism Analysis in 81 Japanese Patients

Department of Pediatrics, Keio University School of Medicine (G.S., T.I., K.K., T.T., T.H.), Tokyo 160-8582; National Research Institute for Child Health and Development (T.O.), Tokyo 154-8567; Department of Pediatrics, Saitama Municipal Hospital (S.S.), Saitama 336-8522; Department of Laboratory Medicine, Keio University School of Medicine (K.H.), Tokyo 160-8582; and National Center for Child Health and Development (N.M.), Tokyo 157-8535, Japan

Address all correspondence and requests for reprints to: Dr. Goro Sasaki, Department of Pediatrics, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. E-mail: g-sasaki{at}dp.u-netsurf.ne.jp.

	Abstract

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The 5-reductase-2 encoded by the SRD5A2 gene plays a critical role in male sex differentiation by converting testosterone into 5 dihydrotestosterone in the peripheral target tissues. In this study, we examined the SRD5A2 gene in 81 Japanese patients with micropenis (age, 0–14 yr; median, 7 yr) whose stretched penile lengths were between -2.5 SD and -2.0 SD in 39 patients (age, 0–13 yr; median, 8 yr) and below -2.5 SD in 42 patients (age, 0–14 yr; median, 6 yr), together with 100 control males (50 boys and 50 fertile adult males). Mutation analysis was performed for exons 1–5 and their flanking introns by denaturing HPLC and direct sequencing, revealing Y26X/R227Q in an 11-yr-old boy with a penile length of -2.6 SD, G34R/R227Q in a 9-yr-old boy with a penile length of -3.6 SD, and R227Q/R227Q in a 3-yr-old boy with a penile length of -2.4 SD, together with heterozygous R227Q in a control boy and a fertile adult male. Polymorphism analysis was carried out for the most frequent V89L known to reduce the enzyme activity by approximately 30% in 78 patients, except for the three patients with SRD5A2 mutations, and in the 100 control males by direct sequencing, showing that allele and genotype frequencies were similar between 78 patients with micropenis below -2.0 SD or 40 patients with micropenis below -2.5 SD and the 100 control males, the 50 boys, or the 50 fertile adult males, with no statistically significant differences.

The results suggest that, in Japanese patients, micropenis can be caused by SRD5A2 gene mutations, especially by R227Q which has been shown to retain approximately 3.2% of normal enzyme activity and appears relatively frequent in Asian populations, and that V89L polymorphism is unlikely to raise the susceptibility to the development of micropenis.

	Introduction

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MICROPENIS IS A HETEROGENEOUS condition defined as significantly small penis that is free from associated external genital ambiguity such as hypospadias (1, 2). It is a quantitative character and can occur either as a single gene disorder or as a multifactorial disorder subject to various genetic and environmental factors (1, 2). Because the development of male external genitalia including penile growth is primarily caused by the biological effects of gonadal androgens, genes involved in the gonadal androgen production and in the peripheral androgen action could be relevant to the development of micropenis (1, 2, 3).

The 5-reductase-2 plays a crucial role in male sex differentiation by converting testosterone (T) into 5 dihydrotestosterone (DHT) in the peripheral target tissues (3). It is known that masculinization of Wolffian ducts is primarily caused by T, whereas that of external genitalia, urethra, and prostate is primarily due to 5DHT (3, 4). Thus, 5-reductase-2 deficiency, although it permits Wolffian development, results in various degrees of male pseudohermaphroditism with undermasculinized external genitalia, primarily depending on the residual enzyme activity (5, 6, 7).

The 5-reductase-2 is encoded by the SRD5A2 gene on chromosome 2p23 (8). The SRD5A2 gene consists of five exons and is expressed in the 5DHT-dependent genital tissues as well as in other organs/tissues, including liver (9, 10). To date, multiple mutations distributed throughout the coding region of the SRD5A2 gene have been identified in patients with 5-reductase-2 deficiency, and phenotypic spectrum in such patients is known to range widely from nearly female external genitalia to apparently male external genitalia (4, 9). Indeed, micropenis phenotype has been reported in a boy with a mutant SRD5A2 gene (11). Furthermore, a polymorphism in the SRD5A2 gene may also be relevant to the development of micropenis by raising the susceptibility to undermasculinization. In this regard, the most frequent polymorphism V89L (ValLeu substitution at the 89th codon) at exon 1 has been shown to decrease 5-reductase-2 activity by approximately 30% (12, 13), and previous studies have suggested that this polymorphism may reduce the susceptibility to androgen-dependent prostate cancer (13, 14). Thus, V89L polymorphism may be more prevalent in patients with micropenis than in normal males.

To our knowledge, however, there has been no report describing a systematic mutation or polymorphism analysis of the SRD5A2 gene in patients with micropenis. Thus, we performed mutation and V89L polymorphism analysis in patients with micropenis.

	Subjects and Methods

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Subjects

Eighty-one consecutive Japanese patients with micropenis (age, 0–14 yr; median, 7 yr) were studied, after obtaining written informed consent; 64 of the 81 patients have been described previously in our study of AR gene analysis (15). The selection criteria included: 1) stretched penile length below -2.0 SD of the mean in age-matched normal Japanese boys (16); 2) lack of hypospadias; 3) no gynecomastia; 4) age- and pubertal tempo-matched basal serum LH, FSH, and T levels; 5) 46,XY karyotype; 6) no definitive AR gene mutation indicated by a heteroduplex detection method and sequencing (15); 7) no recognizable malformation syndromes known to be associated with genital abnormalities; and 8) normal growth and development. Because -2.0 SD has been regarded as the lower limit of normal variations for most quantitative traits and -2.5 SD has been used as the lower limit of normal penile lengths (1, 2), the 81 patients were divided into two groups: group 1–39 patients with small penis between -2.0 and -2.5 SD below the mean (age, 0–13 yr; median, 8 yr); and group 2–42 patients with small penis below -2.5 SD of the mean (age, 0–14 yr; median, 6 yr; thus, the sum of groups 1 and 2 represents the total of 81 patients with micropenis below -2.0 SD). Cryptorchidism was bilaterally present in three patients aged 3, 8, and 13 yr in group 1 and in four patients aged 0, 5, 8, and 11 yr in group 2, and unilaterally present in two patients aged 6 and 9 yr in group 1 (right and left side, respectively) and in two patients aged 3 and 7 yr in group 2 (right and left side, respectively).

For controls, 50 Japanese boys with apparently normal external genitalia who were diagnosed as having idiopathic short stature (age, 3–16 yr; median, 8.5 yr) and 50 Japanese adult males with proven fertility (age, 25–48 yr; median, 38.5 yr) were similarly analyzed with permission. All of the 100 control males had a 46,XY karyotype.

Analysis of the SRD5A2 gene

Leukocyte genomic DNA was amplified for the 5 exons and their flanking introns of the SRD5A2 gene by PCR, using five sets of primers designed on the basis of the previous report (17) and the genomic sequence of the human SRD5A2 gene (GenBank accession no. L03843). The primer sequences and the annealing temperatures are shown in Table 1, together with the PCR product sizes. Subsequently, the PCR products for exon 1 were subjected to direct sequencing from both directions on an ABI PRISM 310 autosequencer (Applied Biosystems, Foster City, CA), to examine a mutation and the V89L (G265C) polymorphism. The PCR products for exons 2–5 were first screened for a mutation by a heteroduplex detection method with a proven sensitivity and specificity of more than 95% (18, 19), and when abnormal heteroduplex patterns were detected, corresponding PCR products were directly sequenced on the autosequencer. For the heteroduplex detection, the PCR products of each patient were mixed with those of a normal male known to have a wild-type sequence and subjected to denaturing HPLC (DHPLC) on an automated instrument (WAVE; Transgenomic, San Jose, CA). The DHPLC melting temperature was calculated by WAVE Maker software version 4.1, and several different temperatures (the calculated temperature and around that temperature) were used for the DHPLC analysis (Table 1).

The statistical significance of the allele and genotype frequencies of the V89L polymorphism was examined by the ² test. P value less than 0.05 was considered significant.

	Results

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SRD5A2 gene mutations

SRD5A2 mutations were identified in three patients (Table 2, cases 1–3). Direct sequencing for exon 1 revealed a heterozygous C78G transversion resulting in a substitution of the 26th tryptophan codon by stop codon (Y26X) in case 1 (Fig. 1A) and a heterozygous G100C transversion leading to a substitution of the 34th glycine codon by arginine codon (G34R) in case 2 (Fig. 1B). Mutation screening for exon 4 detected abnormal chromatograms common to cases 1–3; subsequent direct sequencing revealed a heterozygous G680A transition causing a substitution of the 227th arginine codon by glutamine codon (R227Q) in cases 1 and 2 and a homozygous G680A transition (R227Q) in case 3 (Fig. 1C). The unrelated parents of case 2 and the consanguineous parents of case 3 were shown to be heterozygous for the mutations of cases 2 and 3, respectively (Table 3). In addition, a different type of aberrant chromotogram was found for exon 4 in two other cases, and sequencing analysis revealed a heterozygous silent substitution (T696C, H232H) in the two patients. No other abnormal chromatograms were found for exons 2–5. Y26X and G34R mutations were undetected in the 100 control males, whereas R227Q mutation was identified in a heterozygous status in two control males (a boy and an adult male).

View larger version (22K): [in this window] [in a new window]   FIG. 1. Mutations of the SRD5A2 gene. A, A heterozygous C78G transversion at exon 1, resulting in Tyr26Stop (Y26X) in case 1. B, A heterozygous G100C transversion at exon 1, leading to Gly34Arg (G34R) in case 2. C, A homozygous G680A transition at exon 4, causing Arg227Gln (R227Q) in case 3.

Endocrine studies were also performed for the parents of cases 2 and 3 (Table 3). Basal serum T, 5DHT, FSH, and LH levels were normal, and T/5DHT ratio was normal in the two fathers and at the upper limit in the two mothers. Steroid hormone profile analysis for random urine samples indicated elevated 5ßTHF/5THF ratios in the father of case 2 and the parents of case 3 and increased etiocholanolone/androsterone ratios in the father of case 2 and the mother of case 3.

V89L polymorphism

The V89L polymorphism was analyzed for 78 patients with no demonstrable SRD5A2 mutations (38 patients in group 1, and 40 patients in group 2) and for the 100 control males. The allele (V and L) and genotype (VV, VL, and LL) frequencies were similar between 78 patients with micropenis below -2.0 SD (groups 1 + 2) or 40 patients with micropenis below -2.5 SD (group 2) and the 100 control males, the 50 boys, or the 50 adult males, as well as between the 50 boys and the 50 adult males, with no statistically significant differences (Table 4).

	Discussion

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Mutation analysis showed two missense mutations (G34R and R227Q) and one nonsense mutation (Y26X) of the SRD5A2 gene in three patients with micropenis. The two missense mutations have previously been reported in patients with 5-reductase-2 deficiency (8, 11), and functional studies have indicated that both mutations severely compromise the enzyme activity (8, 12). The nonsense mutation is a novel one and should actually abolish the enzymatic activity, because it drastically truncates the enzyme. Furthermore, the results of parental studies are consistent with compound heterozygosity for G34R and R227Q in case 2 and homozygosity for R227Q in case 3. In addition, it is unlikely that Y26X and R227Q in case 1 resides on the same allele, because 5-reductase-2 deficiency is an autosomal recessive disorder. Thus, although it might be possible that a different type of mutation(s) remained undetected by the DHPLC analysis or existed in an unexamined region such as the promoter and the intron sequences, our results imply that micropenis can be caused by SRD5A2 mutations, with an estimated prevalence of approximately 3.7% (3 of 81) in Japanese patients with micropenis below -2.0 SD and approximately 4.8% (2 of 42) in those with micropenis below -2.5 SD.

Cases 1–3 with SRD5A2 mutations shared R227Q in common. In this regard, several findings are noteworthy: 1) in vitro biochemical studies have shown that R227Q reduces the maximum velocity of enzyme reaction (V_max) to approximately 3.2% of normal activity (12), indicating that R227Q is a hypomorphic mutation retaining a low residual enzymatic activity; 2) missense mutations with less than 0.4% of normal activity usually cause ambiguous or female external genitalia, whereas those with 3–15% of enzymatic activity usually permit masculinization of the external genitalia (3, 24, 25); 3) R227Q mutation has previously been identified in a homozygous status in two Vietnamese brothers only (7, 11), one with micropenis alone and the other with micropenis and hypospadias, and has not been found in patients with ambiguous or female genitalia; 4) TE therapy resulted in subnormal responses in cases 1–3; and 5) a heterozygous R227Q mutation has been identified in two of 100 Japanese control males (this study) and in five Chinese males after examining 543 normal males of various ethnic origins (12). These findings imply that R227Q may be relatively frequent in Asian populations and that the low residual enzyme activity, although it is insufficient for normal male genital development, has permitted a considerable degree of masculinization including micropenis phenotype as well as subnormal response to TE therapy.

Genital findings of cases 1–3 with SRD5A2 mutations are noteworthy in two points. First, case 3 had mild micropenis of -2.4 SD. This implies that even patients with mild micropenis above -2.5 SD may have 5-reductase-2 deficiency. In this regard, because case 3 was homozygous for both R227Q with residual enzyme activity and V allele with high enzyme activity, this may have served to prevent the development of severe micropenis. Second, micropenis was more severe in case 2 than in case 1, and cryptorchidism was observed in case 3. Because R227Q and G34R retain approximately 3.2% and approximately 1.2% of enzymatic activity, respectively (8, 12), and Y26X is predicted to lose both the ligand (T) and the cofactor (nicotinamide adenine dinucleotide phosphate) binding domains (4, 9), the results of mutations, together with those of the V89L polymorphism, suggest that the degree of genital development is not simply dependent on the 5-reductase-2 activity. Indeed, genital development is considered to be subject to multiple genetic and environmental factors such as the AR-mediated signal transduction activity and intrauterine T concentration. In this regard, it is unlikely that cryptorchidism in case 3 is due to his young age, because spontaneous descent is rare after 3 yr of age (26), and his testicular descent occurred after treatment.

Furthermore, several matters appear to be worth pointing out for the diagnostic and therapeutic findings of cases 1–3. First, the hCG stimulated T/5DHT ratio was unequivocally elevated in cases 1–3. This suggests that 5-reductase-2 deficiency can be diagnosed by standard endocrine studies, even in boys with micropenis only phenotype. Second, case 3 showed low T response in the hCG test and slightly high FSH response in the GnRH test, as has occasionally been described in 5-reductase-2 deficiency (11, 27). Although this would be ascribed to secondary testicular dysfunction resulting from cryptorchidism (11, 27), such endocrine data may lead to misdiagnosis of defective testicular steroidogenesis unless the hCG stimulated T/5DHT ratio is examined. Third, urinary steroid hormone profile analysis revealed markedly elevated ratios of 5ß to 5 metabolites, as has been reported previously (28, 29). Although this would primarily be due to defective 5-reductase-2 activity in the liver, which would mainly catalyze adrenal rather than testicular steroid hormones (6, 10, 30), urinary steroid hormone profile analysis is a highly sensitive and noninvasive test and, therefore, appears to be more advantageous than serum androgen measurement for the diagnosis of 5-reductase-2 deficiency. In addition, it can often identify heterozygotes (this study and Ref. 31). Lastly, TE therapy with a standard dosage showed a subnormal effect, and 5DHT gel treatment caused sufficient penile growth. This is consistent with impaired activity of 5-reductase-2 that converts exogenous as well as endogenous T into 5DHT, and it implies that early diagnosis of 5-reductase-2 deficiency enables application of appropriate therapy with 5DHT gel and prevention of adverse effects such as skeletal maturation of TE therapy.

The V89L polymorphism was similar in both allele and genotype frequencies between patients with micropenis and control males. This suggests that V89L polymorphism, although it has been shown to reduce the enzyme activity by approximately 30% (12, 13), had no discernible effect on the development of micropenis in the patients examined here. It remains possible, however, that V89L polymorphism constitutes one of susceptibility factors for the development of androgen-related disorders, so that it may be detected as a positive modifier for micropenis in other patient populations. Indeed, on the basis of an inverse relationship between CAG repeat length at exon 1 and transactivation function or expression level of the AR gene (32, 33), a large number of studies have been performed to examine CAG repeat lengths in patients with androgen-related disorders such as undermasculinization and azoospermia, showing both positive and negative results for the association between expansion of CAG repeat lengths and predisposition to such disorders (15, 34, 35, 36).

In summary, the present study suggests that hypomorphic mutations of the SRD5A2 gene can cause micropenis phenotype in Japanese patients, with R227Q mutation being most prevalent, and that V89L polymorphism is unlikely to raise the susceptibility to the development of micropenis. Further studies will permit better clarification of the relevance of the SRD5A2 gene to the development of micropenis.

	Footnotes

 
This work was supported in part by a grant for Child Health and Development (14-L) from the Ministry of Health, Labour and Welfare, by Pharmacia Fund for Growth and Development Research, and by a grant from Human Science Foundation.

Abbreviations: DHPLC, Denaturing HPLC; DHT, dihydrotestosterone; hCG, human chorionic gonadotropin; T, testosterone; TE, T enanthate; THF, tetrahydrocortisol.

Received September 9, 2002.

Accepted March 26, 2003.

	References

Top Abstract Introduction Subjects and Methods Results Discussion References

 

1. Elder JS 1998 Congenital anomalies of the genitalia. In: Walsh PC, Retik AB, Vaughan Jr ED, Wein AJ, eds. Campbell’s urology. 7th ed. Philadelphia: WB Saunders; 2120–2144
2. Lee PA, Mazur T, Danish R, Amrhein J, Blizzard RM, Money J, Migeon CJ 1980 Micropenis. I. Criteria, etiologies and classification. Johns Hopkins Med J 146:156–163[Medline]
3. Grumbach MM, Conte FA 1998 Disorders of sex differentiation. In: Wilson JD, Foster DW, Kronenberg HM, Larsen PR, eds. Williams textbook of endocrinology. 9th ed. Philadelphia: WB Saunders; 1303–1425
4. Wilson JD, Griffin JE, Russell DW 1993 Steroid 5 -reductase 2 deficiency. Endocr Rev 14:577–593[Abstract/Free Full Text]
5. Walsh PC, Madden JD, Harrod MJ, Goldstein JL, MacDonald PC, Wilson JD 1974 Familial incomplete male pseudohermaphroditism, type 2. Decreased dihydrotestosterone formation in pseudovaginal perineoscrotal hypospadias. N Engl J Med 291:944–949
6. Imperato-McGinley J, Guerrero L, Gautier T, Peterson RE 1974 Steroid 5-reductase deficiency in man: an inherited form of male pseudohermaphroditism. Science 186:1213–1215[Abstract/Free Full Text]
7. Sinnecker GH, Hiort O, Dibbelt L, Albers N, Dorr HG, Hauss H, Heinrich U, Hemminghaus M, Hoepffner W, Holder M, Schnabel D, Kruse K 1996 Phenotypic classification of male pseudohermaphroditism due to steroid 5 -reductase 2 deficiency. Am J Med Genet 63:223–230[CrossRef][Medline]
8. Thigpen AE, Davis DL, Milatovich A, Mendonca BB, Imperato-McGinley J, Griffin JE, Francke U, Wilson JD, Russell DW 1992 Molecular genetics of steroid 5 -reductase 2 deficiency. J Clin Invest 90:799–809
9. Russell DW, Wilson JD 1994 Steroid 5 -reductase: two genes/two enzymes. Annu Rev Biochem 63:25–61[Medline]
10. Thigpen AE, Silver RI, Guileyardo JM, Casey ML, McConnell JD, Russell DW 1993 Tissue distribution and ontogeny of steroid 5 -reductase isozyme expression. J Clin Invest 92:903–910
11. Hiort O, Willenbring H, Albers N, Hecker W, Engert J, Dibbelt L, Sinnecker GH 1996 Molecular genetic analysis and human chorionic gonadotropin stimulation tests in the diagnosis of prepubertal patients with partial 5 -reductase deficiency. Eur J Pediatr 155:445–451[CrossRef][Medline]
12. Makridakis NM, di Salle E, Reichardt JK 2000 Biochemical and pharmacogenetic dissection of human steroid 5 -reductase type II. Pharmacogenetics 10:407–413[CrossRef][Medline]
13. Makridakis N, Ross RK, Pike MC, Chang L, Stanczyk FZ, Kolonel LN, Shi CY, Yu MC, Henderson BE, Reichardt JK 1997 A prevalent missense substitution that modulates activity of prostatic steroid 5-reductase. Cancer Res 57:1020–1022[Abstract/Free Full Text]
14. Lunn RM, Bell DA, Mohler JL, Taylor JA 1999 Prostate cancer risk and polymorphism in 17 hydroxylase (CYP17) and steroid reductase (SRD5A2). Carcinogenesis 20:1727–1731[Abstract/Free Full Text]
15. Ishii T, Sato S, Kosaki K, Sasaki G, Muroya K, Ogata T, Matsuo N 2001 Micropenis and the AR gene: mutation and CAG repeat-length analysis. J Clin Endocrinol Metab 86:5372–5378[Abstract/Free Full Text]
16. Fujieda K, Matsuura N 1987 Growth and maturation in the male genitalia from birth to adolescence II: change of penile length. Acta Paediatr Jpn 29:220–223[Medline]
17. Boudon C, Lumbroso S, Lobaccaro JM, Szarras-Czapnik M, Romer TE, Garandeau P, Montoya P, Sultan C 1995 Molecular study of the 5 -reductase type 2 gene in three European families with 5 -reductase deficiency. J Clin Endocrinol Metab 80:2149–2153[Abstract]
18. Wagner TM, Hirtenlehner K, Shen P, Moeslinger R, Muhr D, Fleischmann E, Concin H, Doeller W, Haid A, Lang AH, Mayer P, Petru E, Ropp E, Langbauer G, Kubista E, Scheiner O, Underhill P, Mountain J, Stierer M, Zielinski C, Oefner P 1999 Global sequence diversity of BRCA2: analysis of 71 breast cancer families and 95 control individuals of worldwide populations. Hum Mol Genet 8:413–423[Abstract/Free Full Text]
19. O’Donovan MC, Oefner PJ, Roberts SC, Austin J, Hoogendoorn B, Guy C, Speight G, Upadhyaya M, Sommer SS, McGuffin P 1998 Blind analysis of denaturing high-performance liquid chromatography as a tool for mutation detection. Genomics 52:44–49[CrossRef][Medline]
20. Japan Public Health Association 1996 Normal biochemical values in Japanese children. Tokyo: Sanko Press (in Japanese)
21. Muroya K, Okuyama T, Goishi K, Ogiso Y, Fukuda S, Kameyama J, Sato H, Suzuki Y, Terasaki H, Gomyo H, Wakui K, Fukushima Y, Ogata T 2000 Sex determining gene(s) on distal 9p: clinical and molecular studies in six cases. J Clin Endocrinol Metab 85:3094–3100[Abstract/Free Full Text]
22. Ito J, Tanaka T, Horikawa R, Okada Y, Morita S, Koitaji M, Tanae A, Hibi I 1993 Serum LH and FSH levels during GnRH tests and sleep in children. J Jpn Pediatr Soc 97:1789–1796 (in Japanese)
23. Choi SK, Han SW, Kim DH, de Lignieres B 1993 Transdermal dihydrotestosterone therapy and its effects on patients with microphallus. J Urol 150:657–660[Medline]
24. Wigley WC, Prihoda JS, Mowszowicz I, Mendonca BB, New MI, Wilson JD, Russell DW 1994 Natural mutagenesis study of the human steroid 5 -reductase 2 isozyme. Biochemistry 33:1265–1270[CrossRef][Medline]
25. Forti G, Falchetti A, Santoro S, Davis DL, Wilson JD, Russell DW 1996 Steroid 5 -reductase 2 deficiency: virilization in early infancy may be due to partial function of mutant enzyme. Clin Endocrinol (Oxf) 44:477–482[CrossRef][Medline]
26. Griffin JE, Wilson JD 1998 Disorders of the testes and the male reproductive tract. In: Wilson JD, Foster DW, Kronenberg HM, Larsen PR, eds. Williams textbook of endocrinology. 9th ed. Philadelphia: WB Saunders; 819–875
27. Mendonca BB, Inacio M, Costa EM, Arnhold IJ, Silva FA, Nicolau W, Bloise W, Russel DW, Wilson JD 1996 Male pseudohermaphroditism due to steroid 5-reductase 2 deficiency. Diagnosis, psychological evaluation, and management. Medicine (Baltimore) 75:64–76[CrossRef][Medline]
28. Imperato-McGinley J, Peterson RE, Gautier T, Cooper G, Danner R, Arthur A, Morris PL, Sweeney WJ, Shackleton C 1982 Hormonal evaluation of a large kindred with complete androgen insensitivity: evidence for secondary 5 -reductase deficiency. J Clin Endocrinol Metab 54:931–941[Abstract/Free Full Text]
29. Peterson RE, Imperato-McGinley J, Gautier T, Shackleton C 1985 Urinary steroid metabolites in subjects with male pseudohermaphroditism due to 5 -reductase deficiency. Clin Endocrinol (Oxf) 23:43–53[Medline]
30. Fisher LK, Kogut MD, Moore RJ, Goebelsmann U, Weitzman JJ, Isaacs Jr H, Griffin JE, Wilson JD 1978 Clinical, endocrinological, and enzymatic characterization of two patients with 5 -reductase deficiency: evidence that a single enzyme is responsible for the 5 -reduction of cortisol and testosterone. J Clin Endocrinol Metab 47:653–664[Abstract/Free Full Text]
31. Imperato-McGinley J, Peterson RE, Gautier T, Arthur A, Shackleton C 1985 Decreased urinary C19 and C21 steroid 5 -metabolites in parents of male pseudohermaphrodites with 5 -reductase deficiency: detection of carriers. J Clin Endocrinol Metab 60:553–558[Abstract/Free Full Text]
32. Chamberlain NL, Driver ED, Miesfeld RL 1994 The length and location of CAG trinucleotide repeats in the androgen receptor N-terminal domain affect transactivation function. Nucleic Acids Res 22:3181–3186[Abstract/Free Full Text]
33. Choong CS, Kemppainen JA, Zhou Z, Wilson EM 1996 Reduced androgen receptor gene expression with first exon CAG repeat expansion. Mol Endocrinol 10:1527–1535[Abstract/Free Full Text]
34. Lim HN, Chen H, McBride S, Dunning AM, Nixon RM, Hughes IA, Hawkins JR 2000 Longer polyglutamine tracts in the androgen receptor are associated with moderate to severe undermasculinized genitalia in XY males. Hum Mol Genet 9:829–834[Abstract/Free Full Text]
35. Dowsing AT, Yong EL, Clark M, McLachlan RI, de Kretser DM, Trounson AO 1999 Linkage between male infertility and trinucleotide repeat expansion in the androgen-receptor gene. Lancet 354:640–643[CrossRef][Medline]
36. Dadze S, Wieland C, Jakubiczka S, Funke K, Schroder E, Royer-Pokora B, Willers R, Wieacker PF 2000 The size of the CAG repeat in exon 1 of the androgen receptor gene shows no significant relationship to impaired spermatogenesis in an infertile Caucasoid sample of German origin. Mol Hum Reprod 6:207–214[Abstract/Free Full Text]

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