SHFM is a heterogeneous condition caused by abnormalities at one of multiple loci, including SHFM1 (SHFM1 at 7q21-q22), SHFM2 (Xq26), SHFM3 (FBXW4/DACTYLIN at 10q24), SHFM4 (TP63 at 3q27), and SHFM5 (DLX1 and DLX 2 at 2q31). SHFM3 is unique in that it is caused by submicroscopic tandem chromosome duplications of FBXW4/DACTYLIN. SHFM3 is considered isolated ectrodactyly and does not show a mutation of the tp63 gene. Presentation
Ectrodactyly can be caused by various changes to 7q. When 7q is altered by a deletion or a translocation, ectrodactyly can sometimes be associated with hearing loss. Ectrodactyly, or Split hand/split foot malformation (SHFM) type 1 is the only form of split hand/ malformation associated with sensorineural hearing loss. Genetics
A large number of human gene defects can cause ectrodactyly. The most common mode of inheritance is autosomal dominant with reduced penetrance, while autosomal recessive and X-linked forms occur more rarely. Ectrodactyly can also be caused by a duplication on 10q24. Detailed studies of a number of mouse models for ectrodactyly have also revealed that a failure to maintain median apical ectodermal ridge (AER) signalling can be the main pathogenic mechanism in triggering this abnormality.A number of factors make the identification of the genetic defects underlying human ectrodactyly a complicated process: the limited number of families linked to each split hand/foot malformation (SHFM) locus, the large number of morphogens involved in limb development, the complex interactions between these morphogens, the involvement of modifier genes, and the presumed involvement of multiple gene or long-range regulatory elements in some cases of ectrodactyly.
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