- - gonadal d. defective gonadal development, varying types and degrees of which have been identified, including gonadal aplasia or agenesis, rudimentary gonads, congenitally defective gonads, and true hermaphroditism; the character of the external genitalia, genital ducts, and secondary sexual development are only sometimes uniquely related to a given type of gonadal d. XO gonadal d. consists of monosomy X with a gonadal streak rather than a true ovary, notably seen in Turner syndrome; XX gonadal d. is an autosomal recessive disorder with a female karyotype, streaked gonads, and primary amenorrhea, but with no body features of Turner syndrome; XY gonadal d. is an X-linked disorder associated with a male karyotype and a female habitus, streaked gonads, and absence of secondary sexual characteristics.- iridocorneal mesenchymal d. d. of cornea and iris, producing pupillary anomalies, posterior embryotoxon, and secondary glaucoma, resulting in part from anomalous development of the ocular mesenchyme.- seminiferous tubule d. rarely used term for a disorder in which the seminiferous tubules exhibit an abnormal cytoarchitecture and extensive hyalinization; the testes are small, and few spermatozoa are formed; the body habitus may be eunuchoid, and gynecomastia may be present; urinary gonadotropin output is usually high, and the incidence of mental deficiency and illness increased; sex chromatin may be male or female, and androgen secretion ranges from subnormal to normal. It is a constant feature of (and the term may be used synonymously with) Klinefelter syndrome. SYN: germinal aplasia.- testicular d. [MIM*305700] a congenital derangement of seminiferous tubular structure and function, resulting in male infertility; the defect in spermatogenesis may be incomplete, as in maturational arrest or premature sloughing, or spermatogenesis may be completely absent, as in the Sertoli-cell-only syndrome.
* * *dys·gen·e·sis (')dis-'jen-ə-səs n, pl -e·ses -.sēz defective development esp. of the gonads (as in Klinefelter's syndrome or Turner's syndrome)
* * *n.faulty development. Gonadal dysgenesis is failure of the ovaries or testes to develop (see Turner's syndrome).
* * *dys·gen·e·sis (dis-jenґə-sis) defective development; see also dysplasia and dyspoiesis.
Medical dictionary. 2011.