Beginnings, Growth and DevelopmentThis page introduces the statistical data associated with birth abnormalities in the genital system in Australia and also briefly introduces some of these defects for more detailed coverage look at the Genital Abnormalities Notes.
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Note that some abnormalites affect physiological function, while others through mainly perturbed endocrine effects, can impact upon not only other systems but also have neurological ramifications upon sexual identity. Then finally look at the online informatin provided to the general public on birth defects associated with genital system development and sexuality.
Genital abnormalities fall into several categories: chromosomal, hermaphroditism, gonadal dysfunction, tract abnormalities, external genitalia and gonadal descent (More? Genital Abnormalities). To find more details about specific abnormalities use the OMIM link.
Study the statistical data below and compare the relative contribution of defects in the genital system to the overall data on abnormalities. Note urinary system defects may also impact upon the genital system.
Birth Defects by System
Data shown as a % of all Major Abnormalities based upon published Australian Statistics (1981-1992) using the same groupings as Congenital Malformations Australia 81-92.
Birth Defects Total Number
Defect Rate / 10,000 Births
Turner's Syndrome: Monosomy XO, 99% non-viable embryos, fail to sexually mature at puberty.
Klinefelter's Syndrome: 47, XXY, begin normal male, become infertile. Features tall, mental dullness, behaviour problems
Males 46, XX, Develop as male, infertile adults, portion of SRY gene located on one X.
Search the OMIM Database: Pseudohermaphrodite | Turner's Syndrome
True: 46,XX, Gonads both ovary and teste tissues, Ovotestes or ovary and testes
Male Pseudohermaphrodites: 46,XY, Gonads of one sex, external genitalia of opposite, Various causes
Female Pseudohermaphrodites: 46,XX, Gonads are ovaries, external genitalia ambiguous, Hyperplastic adrenals secrete androgens
Search the OMIM Database: Hermaphrodite | Pseudohermaphrodite
Gonads fail to develop properly.
Gonadal Dysgenesis: 46,XX, Swyer's syndrome
Mixed Gonadal Dysgenesis: 45,X/46,XY
Primary Hypogonadism: 46,XX, affected females
Primary Hypogonadism: Defective anterior pituitary production of gonadotropin, lack of gonadotropin-releasing hormone
Search the OMIM Database: Hypogonadism
Many different forms
Uterine: Associated with other anomolies
Vagina: Agenesis, atresia See endocrine lecture DES
Ductus Deferens: Unilateral or bilateral absence, failure of mesonephric duct to differentiate
Links: Notes - Genital Abnormalities | Undescended Testicle or Cryptorchidism
Search the OMIM Database: Cryptorchidism |
Hypospadis most common penis abnormality (1 in 300) resulting from a failure of male urogenital folds to fuse in various regions.
Links: Notes - Genital Abnormalities
Search the OMIM Database: Hypospadia
Medline (USA) provides information on birth defects. Look at the information they provide the general public on specific conditions.
Other resources include:
Online Mendelian Inheritance in Man is a database and a catalog of human genes and genetic disorders.
Search the OMIM Database: SRY | DAX1 | Cryptorchidism | Hydrocele | Hermaphrodite | Pseudohermaphrodite | Turner's Syndrome | Klinefelter's Syndrome | Hypogonadism | Androgen Insensitivity Syndrome | Hypospadia | Vagina | Deferens |
Virtual Children's Hospital: Australia | USA
Link to next page in this Practical - External Genitalia
Finally look at the process of differentiation of the male and female external genitalia.
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