Congenital limb deficiencies in Alberta—a review of 33 years (1980–2012) from the Alberta Congenital Anomalies Surveillance System (ACASS)

Abstract

The birth prevalence of limb deficiencies in Alberta has been fluctuating. The objectives were to examine patterns and temporal trends of congenital limb deficiencies in Alberta and compare rates with those of other jurisdictions. The Alberta Congenital Anomalies Surveillance System data on live births, stillbirths, and terminations of pregnancy (<20 weeks gestation) occurring between 1980 through 2012 with the ICD-10 Royal College of Paediatrics and Child Health Adaptations codes Q71-Q73 (limb reduction defects), Q79.80 (congenital constriction bands), and Q87.24 (sirenomelia syndrome) were reviewed. Cases were classified as having amelia, transverse, longitudinal (preaxial, postaxial, central, or mixed), intercalary, split hand/split foot, complex, or other type of limb deficiency. Phenotypes were classified as associated, which included cases with a known etiology and cases with at least one other type of anomaly, or isolated. From 1980 through 2012, 795 cases were ascertained from 1,411,652 live births and stillbirths, giving a prevalence of 5.6/10,000 total births. Mixed longitudinal deficiencies were the most common (22.4%). The upper limbs (63.9%) were affected more often than the lower limbs (25.3%). Isolated limb deficiencies occurred in 43.6% of cases, 28.4% had Mendelian or other known conditions, 21.9% had multiple congenital anomalies, 5.4% had chromosome abnormalities and 0.6% were due to teratogens. The associated group, showed a significant increasing trend (P = 0.023). While the overall limb deficiency rates show very little differences across diverse populations and differing time periods, comparisons of subgroups should be made with caution, because variations in terminology and classification contribute to reported differences.

Morphology of early intrauterine deaths with full trisomy 15

“…The incidence of a split hand/foot is even more rare (0.5/10 000; 0.05%). 15,16 The high incidence of limb reduction defects among embryonic miscarriages with full trisomy 15 detected by embryoscopy in the present study, and another case of a split hand in a minimal expression recorded in a liveborn with mosaic trisomy 15, 17 indicate that limb reduction defects and craniofacial abnormalities are a common feature of trisomy 15. The strong association of transverse limb reduction defects with trisomy 15 has not been reported previously in the published literature.…”

“…The incidence of limb reduction defects in our cohort is 22% (10 embryos with a terminal transverse limb reduction defect, 3 with a split hand), which is much higher than that reported in live births (5.6/10 000; 0.6%). The incidence of a split hand/foot is even more rare (0.5/10 000; 0.05%) …”

Congenital limb reduction defects in 1.6 million births in Argentina

“…Transverse terminal and longitudinal preaxial are the most common anatomic subtypes reported in the literature, but there is variation in the relative distribution of each subtype. For transverse terminal defects, Riaño et al () reported 49.3% and Castilla et al () 43.3%; whereas Lin et al (), Froster‐Iskenius and Baird (), Gold et al () and Bedard et al () reported 35.1, 34.2, 28.9, and 18.9%, respectively. In populations in which transverse terminal defects are less common, there is an increase in longitudinal defects, particularly preaxial.…”

“…In populations in which transverse terminal defects are less common, there is an increase in longitudinal defects, particularly preaxial. For longitudinal defects, Riaño et al () reported 27.4% (9.6% postaxial and SH/SF complex), Castilla et al () 23.1% (13.1% preaxial), Froster‐Iskenius and Baird () 46.8% (27.6% preaxial), Lin et al () 51.3% (26.2% split hand/split foot), Gold et al () 54.1% (24.7% preaxial), and Bedard et al () 66.0% (22.4% preaxial and postaxial combined).…”

“…Among transverse defects, the most common subtype reported is terminal (Bedard et al, ; Gold et al, ; Riaño et al, ; Stoll et al, ). For longitudinal defects, there are differences between studies as to which subtype is more prevalent: preaxial is usually reported as the more frequent, but Lin et al (1993) and Bedard et al () reported that the most common longitudinal defects were split hand/split foot (SH/SF) complex and preaxial and postaxial combined, respectively.…”