The major locus for dominant preaxial polydactyly in humans has been mapped to 7q36. In mice the dominant Hemimelic extra toes (Hx) and Hammertoe (Hm) mutations map to a homologous chromosomal region and cause similar limb defects. The Lmbr1 gene is entirely within the small critical intervals recently defined for both the mouse and human mutations and is misexpressed at the exact time that the...

The thymidine analogue, 5-bromo-2'-deoxyuridine (BUdR), given at the proper dose and time to pregnant rats produces preaxial hindlimb polydactyly in a high proportion of near term foetuses. The lack of physiological cell death in an area of preaxial mesenchyme known as the foyer primaire preaxial (fpp) is thought to be important in the pathogenesis of this defect. This study addresses the quest...

Background and purpose - Preaxial polydactyly of the foot is a rare malformation and clinicians are often unfamiliar with the associated malformations and syndromes. In order to give guidelines for diagnostics and referral to a clinical geneticist, we provide an overview of the presentation using a literature review and our own patient population. Patients and methods - The literature review wa...

An enhancer named MFCS1 regulates Sonic hedgehog (Shh) expression in the posterior mesenchyme of limb buds. Several mutations in MFCS1 induce ectopic Shh expression in the anterior limb bud, and these result in preaxial polydactyly (PPD). However, the molecular basis of ectopic Shh expression remains elusive, although some mutations are known to disrupt the negative regulation of Shh expression...

this case report presents a case of fanconi’s anemia with an unusual thumb polydactyly in a 2-year old boy. the extra thumb had no nail, nail bed and distal phalanx. the extra thumb had no active motion.the duplication of the thumb occurred at the carpometacarpal joint but its morphology did not match with any classification described for thumb polydactyly. although his thumb polydactyly was ap...

Focal musculoskeletal anomalies vary, and can manifest as part of a syndrome or be accompanied by numerous other conditions such as genetic disorders, karyotype abnormalities, central nervous system anomalies and other skeletal anomalies. Isolated focal musculoskeletal anomaly does, however, also occur; its early prenatal diagnosis is important in deciding prenatal care, and also helps in couns...

Polydactyly is a common congenital digital variation of the hand and foot, which is characterized by supernumerary digits. This condition can occur in one limb or can be exceptionally present in all four limbs; a condition called tetrapolydactyly. It may appear as isolated or in association with other birth defects. Polydactyly might be pre-axial, postaxial and central type, the post-axial bein...

In most of the reported pedigrees on human polydactyly, the manifestation of the trait has been attributed to a single autosomal dominant gene. That this gene is not always penetrant and exhibits a great degree of variable expressibility has been stressed by various authors (listed by Gates, 1946, and McKusick, 1966). By contrast, recessive polydactyly has been described by only a few authors (...