Hawkinsinuria is an autosomal dominant metabolic disorder affecting the metabolism of tyrosine.Normally, the breakdown of the amino acid tyrosine involves the conversion of 4-hydroxyphenylpyruvate to homogentisate by 4-hydroxyphenylpyruvate dioxygenase. Complete deficiency of this enzyme would lead to tyrosinemia III. In rare cases, however, the enzyme is still able to produce the reactive intermediate 1,2-epoxyphenyl acetic acid, but is unable to convert this intermediate to homogentisate. The intermediate then spontaneously reacts with glutathione to form 2-L-cystein-S-yl-1,4-dihydroxy-cyclohex-5-en-1-yl acetic acid (hawkinsin).Patients present with metabolic acidosis during the first year of life, and growth arrest around the time of weaning off breast milk. Treatment involves a diet containing a low amount of phenylalanine and tyrosine. Tolerance toward these amino acids normalizes as the patients get older. Then only a chlorine-like smell of the urine indicates the presence of the condition. Patients have a normal life and do not require treatment or a special diet.The production of hawkinsin is the result of a gain-of-function mutation. Inheritance of hawkinsinuria is therefore autosomal dominant (presence of a single mutated copy of the gene causes the condition). The gene affected is the HPD gene encoding 4-hydroxyphenylpyruvic acid dioxygenase, on chromosome 12q24. It is unusual in that most other inborn errors of metabolism are caused by loss-of-function mutations, and hence have recessive inheritance (condition occurs only if both copies are mutated). See also
4-Hydroxyphenylpyruvate dioxygenase

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A myxoid liposarcoma is a malignant adipose tissue neoplasm of myxoid appearance histologically. Myxoid liposarcomas are the second-most common type of liposarcoma, representing 30–40% of all liposarcomas in the limbs, occurring most commonly in the legs, particularly the thigh, followed by the buttocks, retroperitoneum, trunk, ankle, proximal limb girdle, head and neck, and wrist. They occur in the intermuscular fascial planes or deep-seated areas. They present as a large, slow-growing, painless mass.The neoplastic cells in these neoplasms contain chromosomal translocations which create one of two fusion genes: the FUS-DDIT3 in ~90% and the EWSR1-DDIT3 fusion gene in up to 10% of myxoid liposarcoma cases. The FUS-DDIT3 fusion gene forms by a merger of part of the FUS FET gene family gene normally located at band 11.2 on the short (or "p") arm of chromosome 16 with part of the DDIT3 ETS transcription factor family gene normally located at band 13.3 on the long (or "q") arm of chromosome 12. This fusion gene is notated as t(12;16)(q13;p11). Preclinical studies, i.e. laboratory studies, suggest that the FUS-DDIT3 fusion gene may act as an oncogene to promote the development of myxoid liposarmas. The EWSR1-DDIT3 fusion gene forms by a merger of the EWSR1 FET gene family gene located at band 12.2 on the q arm of chromosome 22 with part of the DDIT3 gene. This fusion gene is notated as t(12;22)(q13;12). Additional images
See also
Lipoma
Trabectedin

References
External links
Myxoid liposarcoma: a rare soft-tissue tumor with a misleading benign appearance
Efficacy of first-line doxorubicin and ifosfamide in myxoid liposarcoma. 2012