Ten genes have been identified with autosomal dominant inheritance. One of these, SPG4, accounts for ~50% of all genetically solved cases, or approximately 25% of all HSP cases. Twelve genes are known to be inherited in an autosomal recessive fashion. Collectively this latter group account for ~1/3 cases.Most altered genes have known function, but for some the function havent been identified yet. All of them are listed in the gene list below, including their mode of inheritance. Some examples are spastin (SPG4) and paraplegin (SPG7) are both AAA ATPases. Genotypes
The genes are designated SPG (Spastic gait gene). The gene locations are in the format: chromosome - arm (short or p: long or q) - band number. These designations are for the human genes only. The locations may (and probably will) vary in other organisms. Despite the number of genes known to be involved in this condition ~40% of cases have yet to have their cause identified. In the table below SPG? is used to indicate a gene that has been associated with HSP but has not yet received an official HSP gene designation. Pathophysiology
The major feature of HSP is a length-dependent axonal degeneration. These include the crossed and uncrossed corticospinal tracts to the legs and fasciculus gracilis. The spinocerebellar tract is involved to a lesser extent. Neuronal cell bodies of degenerating axons are preserved and there is no evidence of primary demyelination. Loss of anterior horn cells of the spinal cord are observed in some cases.
Presently such a program does not exist in the community, but a community of practice has formed to address this deficiency. Women with POI perceive lower social support than control women, so building a trusted community of practice for them would be expected to improve their well-being. Also, when having that social support, it often helps with reducing stress and having better coping skills. It is important to connect women with POI to an appropriate collaborative care team because the condition has been clearly associated with suicide related to the stigma of infertility. Suicide rates are known to be increased in women who experience infertility. Epidemiology
The prevalence increases with age and is approximately 1 in 10,000 women under age 20, 1 in 1,000 women under age 30, and one percent by age of 40. History
Fuller Albright et al. in 1942 reported a syndrome with amenorrhea, estrogen deficiency, menopausal FSH levels, and short stature. They used the term "primary ovarian insufficiency" to distinguished POI from ovarian insufficiency secondary to a primary failure of pituitary FSH and other hormonal secretion. POI has been described as a more accurate and less stigmatizing term than premature ovarian failure or premature menopause.Chapter 28 of the early Qing dynasty work Fù Qīngzhǔ Nǚkē (《傅青主女科》Fù Qīngzhǔs Gynecology) describes the cause and appropriate treatment for premature menopause. 年未老经水断 (niánwèilǎo jīngshuǐduàn) glosses as not yet old, menstrual water cut-off. References
External links
Primary Ovarian Insufficiency (POI): Overview National Institutes of Health