Limb reduction defects in over one million consecutive livebirths

Abstract

Limb reduction defects occurring among 1,213,913 consecutive livebirths in British Columbia during the period 1952-1984 inclusive were reviewed. A total of 659 cases of limb reduction defects were identified, 393 of them involving the long bones and 190 of them more than one limb. The time period 1966-1984, during which ascertainment was consistent, was evaluated, and an incidence of 5.97 per 10,000 livebirths (1 in 1,692 live births) was found. The data were evaluated for trends over time, sex ratio, and regional and ethnic distribution. Associated anomalies of other organ systems in these cases were analyzed, and overall about one-half of the cases have additional defects. The majority of these additional defects affect the musculoskeletal system and include such entities as clubfoot, hip dislocation, and congenital contractures. Defects are also frequent in other organ systems, such as the cardiovascular, gastrointestinal, and genitourinary systems. By far the most common limb defects are terminal longitudinal defects then terminal transverse defects. Of all cases of limb defects, 75% are upper limb and 25% lower limb. We found no evidence that one side is affected more frequently. About 6.5% of cases had another family member registered with a skeletal defect; 12.9% of cases died within the first year of life, the majority (85%) of those dying having additional defects. Etiological considerations are discussed for some subgroups.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical, genetic, and molecular aspects of split‐hand/foot malformation: An update

“…While the term "ectrodactyly" is commonly used to denote SHFM and has been incorporated into the names of some syndromal forms of SHFM, it is a nonspecific term describing digital absence in any form, and its use should thus be discouraged. SHFM occurs in 1 in 8,500-25,000 newborns and accounts for 8-17% of all limb reduction defects [Froster-Iskenius and Baird, 1989;Calzolari et al, 1990;. Both syndromal and nonsyndromal forms of SHFM are observed, with highly variable clinical expressivity, even among members of the same family and between the limbs of a single individual.…”

Maternal factors, medications, and drug exposure in congenital limb reduction defects.

“…This is not significantly different from the incidence of distal defects occurring among live births in general, where distal defects occurred in 76% of cases and proximal defects in 24% of cases (6). A high incidence of distal limb defects was also found in studies of mammals (28).…”

“…Exposure to Medications, X-Rays, Environmental Hazards, and Drugs Thalidomide was noted in only three cases (Table 6) in this study (6). One of the cases also had prenatal alcohol exposure.…”

“…The data are derived from a large study on limb reduction defects occurring in 1,213,913 consecutive live births in the province of British Columbia during a 30-year period from 1952 to 1984 (6 (6,7).…”

“…Incidence rates for various categories of limb reduction defects, and analysis of upper and lower limb defects aimed at identifying specific patterns of congenital malformations have been published previously (6,8). However, the aspect of possible teratogenic exposures and their role in limb defect causation required a more detailed evaluation.…”