Hand and foot postaxial polydactyly: Two different traits

Abstract

The aim of this work was to test whether postaxial hexadactyly had different clinical and epidemiological characteristics depending on hand or foot involvement. In the period 1967-1993, the Latin-American Collaborative Study of Congenital Malformations (ECLAMC) enrolled 1,582,289 births, and 2,271 cases with isolated (nonsyndromal) postaxial polydactyly (5th-digit hexadactyly). The prevalence was 14.3/10,000 births. Postaxial polydactyly (PP) of the hand (HPP) was the most frequent type (N:1,733; 76.3%; prevalence: 11.0/10,000), followed by foot PP (FPP=N:351; 15.5%; prevalence: 2.2), and hand and foot PP (BPP=N:187; 8.2%; prevalence: 1.2). Unlike HPP (55.0% bilateral; 77.2% left), FPP was less frequently bilateral (19.4%), with lower preference for the left side (55.5%). As expected, HPP was associated with African Black ethnicity, male sex, twinning, low maternal education, parental consanguinity, and there was frequent recurrence in 1st-degree relatives. Conversely, FPP was associated with Amerindian racial background, parental subfertility, and bleeding in the 1st trimester of pregnancy. BPP displayed the highest frequency of associated congenital defects (23.4%, vs HPP:6.6%, FPP: 15.4%). In its isolated form, BPP resembled HPP more than FPP with respect to left preference (90.9%), familial recurrence (11.0% of 1st degree relatives), and low maternal education. Although male sex preference and high frequency of twinning was observed in the 3 PP subtypes, statistical significance was present only in HPP. None of the 3 PP subtypes showed abnormal values for perinatal mortality, birth weight, length of gestation, parental ages, or parity. A logistic regression analysis showed Black race only to be associated with HPP, parental subfertility with FPP, parental consanguinity with BPP, and non-Black race with both FPP and BPP. The data presented here are the first indication that HPP and FPP are 2 different entities, with a larger genetic component in HPP than in FPP.

Hexadactyly, A Rare Case

“…Bilateral form displayed the highest frequency of associated congenital defects. [4] These deformities can occur in many varieties, from a simple extension of a distal phalanx, involving carpal or tarsal bones, to a simple or multiple duplications [8].…”

“…Polydactyly is one of the most common skeletal abnormalities [4]. In a Mexican retrospective case-control study the prevalence among 26,670 births was 1.73 in 1,000 live newborns.…”

Epidemiologia das polidactilias: um estudo de casos e controles na população de Pelotas-RS

“…Outros autores relataram uma maior freqüência de casos desta malformação no sexo masculino. Nos trabalhos citados anteriormente, Scott-Emuakpor e Madueke (1976), na Nigéria, relata- Em relação à polidactilia pós-axial da mão, Castilla et al (1997), ao analisarem 1.733 casos ocorridos na América Latina, num período de 26 anos, relataram associação com etnicidade negro-africana, sexo masculino, gemelares, baixa educação materna e consangüinidade parental, sendo também freqüente a recorrência familiar. O atual estudo não detectou associação significativa entre essas características e polidactilia.…”

Preaxial Polydactyly of Foot, Report of a Rare Case

“…Concomitant polydactyly of the hand occurs in one third and syndactyly of toes in one fifth of cases (2). Polydactyly of the foot is less frequent and has a different genetic basis than hand polydactyly (11). We presented a rare case of foot preaxial polydactyly with its concomitant deformities and result of the surgical treatment.…”