A practical approach to intersex in the newborn period.

Sexual determination is a complex process that occurs in an organized sequential manner. When chromosomal, gonadal, or phenotypic sex determination goes awry,intersexuality develops. Advances in molecular biology have made it easier to understand the various phenotypes that are encountered. It is easy to be overwhelmed when reviewing the testosterone synthesis pathway and the intersex differential diagnosis. This article presents a useful approach to the evaluation of the newborn with ambiguous genitalia.

[1]  J. Bertrand,et al.  Familial male pseudohermaphroditism with gynecomastia due to a testicular 17-ketosteroid reductase defect. I. Studies in vivo. , 1971, The Journal of clinical endocrinology and metabolism.

[2]  P. White,et al.  Congenital adrenal hyperplasia due to 21-hydroxylase deficiency. , 2000, Endocrine reviews.

[3]  M. Ferguson-Smith,et al.  PARENTAL AGE AND THE SOURCE OF THE X CHROMOSOMES IN XXY KLINEFELTER'S SYNDROME. , 1964, Lancet.

[4]  P. Jacobs,et al.  Klinefelter's syndrome: an analysis of the origin of the additional sex chromosome using molecular probes , 1988, Annals of human genetics.

[5]  A. Sinclair,et al.  Genetic evidence that ZFY is not the testis-determining factor , 1989, Nature.

[6]  J. Gearhart,et al.  In vitro fertilization is associated with an increased risk of hypospadias. , 1999, The Journal of urology.

[7]  M. Fellous,et al.  True hermaphroditism: genetic variants and clinical management. , 1994, The Journal of pediatrics.

[8]  Collyer,et al.  THE LANCET.: SUNDAY, OCTOBER 12, 1823 , 1823 .

[9]  D. Orth.,et al.  THE ADRENAL CORTEX , 1948 .

[10]  M. Grumbach,et al.  Cytologic tests of chromosomal sex in relation to sexual anomalies in man. , 1958, Recent progress in hormone research.

[11]  Sahar Mansour,et al.  Campomelic dysplasia and autosomal sex reversal caused by mutations in an SRY-related gene , 1994, Nature.

[12]  M. Schwartz.  The 5-Minute Pediatric Consult , 2002 .

[13]  R. E. Peterson,et al.  Steroid 5α-Reductase Deficiency in Man: An Inherited Form of Male Pseudohermaphroditism , 1974, Science.

[14]  M. New,et al.  Congenital adrenal hyperplasia , 1993 .

[15]  P. Mckenna,et al.  Clinical and molecular analysis of XX sex reversed patients. , 1998, The Journal of urology.

[16]  P. Pearson,et al.  Nonrandom inactivation of the Y-bearing X chromosome in a 46,XX individual: evidence for the etiology of 46,XX true hermaphroditism. , 1994, Cytogenetics and cell genetics.

[17]  L. Wilming,et al.  A novel member of the transmembrane serine/threonine kinase receptor family is specifically expressed in the gonads and in mesenchymal cells adjacent to the müllerian duct. , 1994, Development.

[18]  W. Lenz,et al.  Genetic aspects in male hypogonadism. , 1961, Recent progress in hormone research.

[19]  W. Miller,et al.  The genetic and functional basis of isolated 17,20–lyase deficiency , 1997, Nature Genetics.

[20]  W. Miller,et al.  The pathophysiology and genetics of congenital lipoid adrenal hyperplasia. , 1996, The New England journal of medicine.

[21]  A. Braun,et al.  True hermaphroditism in a 46,XY individual, caused by a postzygotic somatic point mutation in the male gonadal sex-determining locus (SRY): molecular genetics and histological findings in a sporadic case. , 1993, American journal of human genetics.

[22]  P N Goodfellow,et al.  SRY and sex determination in mammals. , 1993, Annual review of genetics.

[23]  L. Hsu,et al.  Phenotype/karyotype correlations of Y chromosome aneuploidy with emphasis on structural aberrations in postnatally diagnosed cases. , 1994, American journal of medical genetics.

[24]  K. O. Elliston,et al.  Male pseudohermaphroditism caused by mutations of testicular 17β–hydroxysteroid dehydrogenase 3 , 1994, Nature Genetics.

[25]  R. M. Sharpe,et al.  Are oestrogens involved in falling sperm counts and disorders of the male reproductive tract? , 1993, The Lancet.

[26]  J. Imperato-McGinley.  Sexual Differentiation: Normal and Abnormal , 1983 .

[27]  S. Lumbroso,et al.  A new deletion of the 5α‐reductase type 2 gene in a Turkish family with 5α‐reductase deficiency , 1995 .

[28]  M. Forest,et al.  Congenital adrenal hyperplasia due to point mutations in the type II 3β–hydroxysteroid dehydrogenase gene , 1992, Nature Genetics.

[29]  P. Lebech,et al.  Testicular feminization syndrome and associated gonadal tumors in Denmark , 1992, Acta obstetricia et gynecologica Scandinavica.

[30]  J. Simard,et al.  Molecular basis of human 3β-hydroxysteroid dehydrogenase deficiency , 1995, The Journal of Steroid Biochemistry and Molecular Biology.

[31]  J. Berek,et al.  Dysgerminoma: the role of conservative surgery. , 1996, Gynecologic oncology.

[32]  D. Housman,et al.  Germline mutations in the Wilms' tumor suppressor gene are associated with abnormal urogenital development in Denys-Drash syndrome , 1991, Cell.

[33]  S. Imbeaud,et al.  Molecular genetics of the persistent müllerian duct syndrome: a study of 19 families. , 1994, Human molecular genetics.

[34]  P. Saenger.  New developments in congenital lipoid adrenal hyperplasia and steroidogenic acute regulatory protein. , 1997, Pediatric clinics of North America.

[35]  D. Porteous,et al.  Molecular analysis of chromosome 11 deletions in aniridia-Wilms tumor syndrome. , 1985, Proceedings of the National Academy of Sciences of the United States of America.

[36]  S. Rousseaux,et al.  Achievement of meiosis in XXY germ cells: study of 543 sperm karyotypes from an XY/XXY mosaic patient , 2004, Human Genetics.

[37]  R. Lovell-Badge,et al.  Dax1 antagonizes Sry action in mammalian sex determination , 1998, Nature.

[38]  M. Toublanc,et al.  Clinical and anatomical spectrum in XX sex reversed patients. Relationship to the presence of Y specific DNA‐sequences , 1994, Clinical endocrinology.

[39]  N. Skakkebaek,et al.  Heterogeneity of gonadoblastoma germ cells: similarities with immature germ cells, spermatogonia and testicular carcinoma in situ cells , 1997, Histopathology.

[40]  M. Marcelli,et al.  Molecular determinants of sexual differentiation , 2004, World Journal of Urology.

[41]  E. Hook,et al.  The distribution of chromosomal genotypes associated with Turner's syndrome: livebirth prevalence rates and evidence for diminished fetal mortality and severity in genotypes associated with structural X abnormalities or mosaicism , 2004, Human Genetics.