: 793   Glycine concentrations in the CSF of affected patients are typically more markedly elevated than in plasma, leading to a corresponding elevation in the ratio of glycine concentrations in the cerebral spinal fluid to that in the plasma. This ratio can also be slightly elevated in patients receiving valproic acid. : 811 Glycine encephalopathy (nonketotic hyperglycinemia, or NKH) should not be confused with other metabolic disorders that can produce elevated glycine levels. For example, certain inherited organic acidurias (aka organic acidemias) can produce elevated glycine in plasma and urine, although these disorders are not caused by defects in the glycine cleavage system, and they are not typically accompanied by corresponding elevations of glycine in cerebrospinal fluid (CSF). Glycine encephalopathy is unique in the fact that levels of glycine are disproportionately elevated in CSF (in addition to elevations in blood and urine), whereas CSF glycine levels are normal or near-normal in patients with inherited organic acidurias. Glycine metabolism
Glycine is metabolized in the bodys cells to end products of carbon dioxide and ammonia. The glycine cleavage system, which is responsible for glycine metabolism in the mitochondria is made up of four protein subunits, the P-protein, H-protein, T-protein and L-protein. : 793

Diagnosis
Classification
There are several different forms of glycine encephalopathy, which can be distinguished by the age of onset, as well as the types and severity of symptoms. All forms of glycine encephalopathy present with only neurological symptoms, including intellectual disability (IQ scores below 20 are common), hypotonia, apneic seizures, and brain malformations.
DHT was almost undetectable in cultured fibroblasts from foreskin, epididymis and the presumed "labia majora" whereas in normal males DHT is detected, suggesting impaired DHT formation. Similar conclusions were obtained for participants in a family in the Dominican Republic study in whom high serum concentration ratios of T to DHT and low concentrations of urinary 5a-reduced androgens were observed. This disorder is now known to be due to homozygous or compound heterozygous loss-of-function mutations of the SRD5A2 gene. Society and culture
Sport
In April 2014, the BMJ reported that four elite women athletes with 5-ARD were subjected to sterilization and "partial clitoridectomies" in order to compete in sport. The authors noted that "partial clitoridectomy" was "not medically indicated, does not relate to real or perceived athletic advantage," relating to elevated androgen levels. The athletes were all from developing countries where lifetime access to hormone replacement may prove elusive. Intersex advocates regard this intervention as "a clearly coercive process". Popular culture
In the Nip/Tuck season three episode "Quentin Costa", it is revealed that Quentin Costa had 5-ARD.Jeffrey Eugenides Pulitzer Prize-winning 2002 novel Middlesex is about a young man with 5-ARD. The character was originally born Calliope and raised as a girl, but upon realizing his genetic sex, he transitions into Cal. Notable people
Caster Semenya

See also
Intersex
Disorders of sexual development, pseudohermaphroditism, and ambiguous genitalia
Inborn errors of steroid metabolism
5α-Reductase (I, II)
Androgen (testosterone and dihydrotestosterone)
Ambiguous genitalia
Intersex surgery
Androgen insensitivity syndrome
Congenital adrenal hyperplasia

References
External links
OMIM article
5-Alpha-Reductase Deficiency at eMedicine