| Swyer syndrome Classification and external resources |
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| ICD-10 | Q56.4 |
|---|---|
| ICD-9 | 752.7 |
| OMIM | 306100 |
| DiseasesDB | 31464 |
| MeSH | D006061 |
Swyer syndrome, or XY gonadal dysgenesis, is a type of female hypogonadism in which no functional gonads are present to induce puberty in an otherwise normal girl whose karyotype is then found to be XY. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The International Statistical Classification of Diseases and Related Health Problems 10th Revision ( ICD -10) is a coding of diseases and signs symptoms abnormal findings Q00-Q89 - Congenital malformations and deformations (Q00-Q07 Nervous system ( Anencephaly and similar malformations The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. The Mendelian Inheritance in Man project is a Database that catalogues all the known Diseases with a genetic component, and—when possible—links them The Diseases Database is a free Website that provides information about the relationships between medical conditions Symptoms, and Medications. Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books Hypogonadism is a medical term for a defect of the Reproductive system that results in lack of function of the Gonads ( ovaries or testes) The gonad is the organ that makes Gametes The gonads in males are the Testes and the gonads in Females are the Ovaries. A karyotype is the characteristic Chromosome complement of a Eukaryote Species. Her gonads are found to be nonfunctional streaks. The gonad is the organ that makes Gametes The gonads in males are the Testes and the gonads in Females are the Ovaries. Gonadal dysgenesis generally refers to a condition where gonadal development is abnormal often only presenting streaks of connective tissue so-called streak gonads. Estrogen and progesterone therapy is usually then commenced. Estrogens (US otherwise oestrogens or œstrogens) are a group of Steroid compounds named for their importance in the Estrous cycle, Progesterone is a C-21 Steroid Hormone involved in the Female Menstrual cycle, Pregnancy (supports Gestation The gonads are normally removed surgically because they do not function and may develop cancer. Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled
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Swyer syndrome as a form of "pure gonadal dysgenesis"
There are several forms of gonadal dysgenesis. Gonadal dysgenesis generally refers to a condition where gonadal development is abnormal often only presenting streaks of connective tissue so-called streak gonads. The term “pure gonadal dysgenesis” (PGD) has been used to describe conditions with normal sets of sex chromosomes (e. g. , 46,XX or 46,XY), as opposed to those whose gonadal dysgenesis results from missing all or part of the second sex chromosome. The latter group includes those with Turner syndrome (e. Turner syndrome or Ullrich-Turner syndrome encompasses several conditions of which monosomy X is the most common g. , 45,X) and its variants, as well as those with mixed gonadal dysgenesis and a mixtures of cell lines, some containing a Y chromosome (e. Mixed gonadal dysgenesis is a condition of unusual and asymmetrical gonadal development leading to an unassigned Sex differentiation. g. , 46,XY/45,X).
Thus Swyer syndrome is referred to as PGD, 46,XY, and XX gonadal dysgenesis as PGD, 46,XX. XX gonadal dysgenesis is a type of female Hypogonadism in which no functional ovaries are present to induce Puberty in an otherwise normal girl whose Karyotype [1] Patients with PGD have a normal chromosomal constellation but may have defects of a specific gene on a chromosome.
Pathogenesis
The first known step of sexual differentiation of a normal XY fetus is the development of testes. See Sex differences in humans for permanent sex differences Sexual differentiation is the process of development of the differences between The testicle (from Latin testiculus, diminutive of testis, meaning "witness" virility plural testes) is the male The early stages of testicular formation in the second month of gestation require the action of several genes, of which one of the earliest and most important is SRY, the "sex-determining region of the Y chromosome". History See also History of genetics The existence of genes was first suggested by Gregor Mendel (1822-1884 who in the 1860s studied inheritance SRY ( Sex-determining Region Y) is a Sex -determining Gene on the Y chromosome in the Therians (placental mammals and marsupials Mutations of SRY account for many cases of Swyer syndrome.
When such a gene is defective, the indifferent gonads fail to differentiate into testes, in an XY (genetically male) fetus. The Prenatal development of the Gonads is a part of the Development of reproductive system and sultimately forms the Testes in males and The testicle (from Latin testiculus, diminutive of testis, meaning "witness" virility plural testes) is the male Without testes, no testosterone or antimullerian hormone (AMH) are produced. Testosterone is a Steroid hormone from the Androgen group In mammals testosterone is primarily secreted in the testes of males and the Ovaries Anti-Müllerian hormone (AMH is a Dimeric Glycoprotein that inhibits the development of the Müllerian ducts in a male Embryo. Without testosterone the external genitalia fail to virilize, resulting in normal female genitalia, and the wolffian ducts fail to develop, so no internal male organs are formed. Testosterone is a Steroid hormone from the Androgen group In mammals testosterone is primarily secreted in the testes of males and the Ovaries A sex organ, or primary sexual characteristic, as narrowly defined is any of the anatomical parts of the body which are involved in sexual reproduction and constitute In biology and medicine virilization refers to the biological development of Sex differences, changes which make a Male body different from a Female body Without AMH, the mullerian ducts develop into normal internal female organs (uterus, fallopian tubes, cervix, vagina). The Müllerian ducts (or paramesonephric ducts) are paired ducts of the Embryo which run down the lateral sides of the Urogenital ridge and terminate at The uterus (from the Latin word for womb) is the major Female reproductive organ of most Mammals including Humans One end the The Fallopian tubes, also known as oviducts, uterine tubes, and salpinges ( singular salpinx) are two very fine tubes lined with ciliated The cervix (from Latin "neck" is the lower narrow portion of the Uterus where it joins with the top end of the Vagina. The vagina (from Latin, literally " Sheath " or " Scabbard " is a fibromuscular tubular tract leading from the Uterus
A baby girl is born who is normal in all anatomic respects except that she has nonfunctional streak gonads instead of ovaries or testes. Gonadal dysgenesis generally refers to a condition where gonadal development is abnormal often only presenting streaks of connective tissue so-called streak gonads. "Ovaria" redirects here This is also a proposed section and a Synonym of Solanum. As girls' ovaries normally produce no important body changes before puberty, a defect of the reproductive system typically remains unsuspected in girls with Swyer syndrome until puberty fails to occur.
Diagnosis
Because of the inability of the streak gonads to produce sex hormones (both estrogens and androgens), most of the secondary sex characteristics do not develop. Sex steroids, also known as gonadal steroids, are Steroid hormones that interact with Vertebrate Androgen or Estrogen receptors Estrogens (US otherwise oestrogens or œstrogens) are a group of Steroid compounds named for their importance in the Estrous cycle, Androgen is the generic term for any natural or synthetic compound usually a Steroid Hormone, that stimulates or controls the development and maintenance of masculine Secondary sex characteristics are traits that distinguish the two Sexes of a species but that are not directly part of the Reproductive system. This is especially true of estrogenic changes such as breast development, widening of the pelvis and hips, and menstrual periods. The menstrual cycle is a recurring cycle of physiologic changes that occurs in reproductive-age Females Overt menstruation (where there is blood flow from the Because the adrenal glands can make limited amounts of androgens and are not affected by this syndrome, most of these girls will develop pubic hair, though it often remains sparse. In Mammals the adrenal glands (also known as suprarenal glands) are the triangle-shaped Endocrine glands that sit on top of the Kidneys their
Evaluation of delayed puberty usually reveals elevation of gonadotropins, indicating that the pituitary is providing the signal for puberty but the gonads are failing to respond. Puberty is described as delayed when a boy or girl has passed the usual age of onset of Puberty with no physical or hormonal signs that it is beginning Gonadotropins are Protein Hormones secreted by Gonadotrope cells of the Pituitary gland of Vertebrates Gonadotropin is sometimes The next steps of the evaluation usually include checking a karyotype and imaging of the pelvis. A karyotype is the characteristic Chromosome complement of a Eukaryote Species. The karyotype reveals XY chromosomes and the imaging demonstrates the presence of a uterus but no ovaries (the streak gonads are not usually seen by most imaging). Although an XY karyotype can also indicate a girl with complete androgen insensitivity syndrome, the absence of breasts, and the presence of a uterus and pubic hair exclude the possibility. Androgen insensitivity syndrome (AIS also referred to as androgen resistance syndrome, is a set of disorders of Sexual differentiation caused by Mutations At this point it is usually possible for a physician to make a diagnosis of Swyer syndrome.
Treatment
The consequences of streak gonads to a woman with Swyer syndrome:
- Gonads cannot make estrogen, so the breasts will not develop and the uterus will not grow and menstruate until estrogen is administered. Estrogens (US otherwise oestrogens or œstrogens) are a group of Steroid compounds named for their importance in the Estrous cycle, This is often given through the skin now.
- Gonads cannot make progesterone, so menstrual periods will not be predictable until progestin is administered, still usually as a pill. A progestin is a synthetic progestagen that has progestinic effects similar to Progesterone.
- Gonads cannot produce eggs so conceiving children naturally is not possible. An ovum (plural ova) is a Haploid Female reproductive cell or Gamete. A woman with a uterus but no ovaries may be able to become pregnant by implantation of another woman's fertilized egg (embryo transfer). Embryo transfer refers to a step in the process of in vitro fertilization (IVF whereby one or several Embryos are placed into the Uterus (Citation Needed)
- Streak gonads with Y chromosome-containing cells have a high likelihood of developing cancer, especially gonadoblastoma. A gonadoblastoma is a complex Neoplasm composed of a mixture of Gonadal elements such as large primordial Germ cells immature Sertoli cells or Streak gonads are usually removed within a year or so of diagnosis since the cancer can begin during infancy.
Gonadal dysgenesis and other similar or related conditions
Swyer syndrome represents one phenotypic result of a failure of the gonads to develop properly, and hence is part of a class of conditions termed gonadal dysgenesis. A phenotype is any observable characteristic of an Organism, such as its morphology, Development, biochemical or physiological properties Gonadal dysgenesis generally refers to a condition where gonadal development is abnormal often only presenting streaks of connective tissue so-called streak gonads. There are many forms of gonadal dysgenesis.
Swyer syndrome is an example of a condition in which an externally unambiguous female body carries dysgenetic, atypical, or abnormal gonads. Other examples include complete androgen insensitivity syndrome, partial X chromosome deletions, lipoid congenital adrenal hyperplasia, and Turner syndrome. Androgen insensitivity syndrome (AIS also referred to as androgen resistance syndrome, is a set of disorders of Sexual differentiation caused by Mutations The X chromosome is one of the two sex-determining Chromosomes in many animal species including mammals (the other is the Y chromosome) Lipoid congenital adrenal hyperplasia is an uncommon form of CAH resulting from defects in the earliest stages of adrenal Cortisol synthesis the transport Turner syndrome or Ullrich-Turner syndrome encompasses several conditions of which monosomy X is the most common
References
External links
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