[The cleft hand. Proposal of a classification based on 279 cleft hands]

A comprehensive functional classification of cleft hand: The DAST concept

Context:

Phenotypic expressions of the congenital cleft hand are variable and might baffle even the experienced as to the choice of surgery. The morphological parameters defining the anomaly dictate not only the functional capacity of the anomalous hand but also the degree of possible surgical restoration. Despite a large number of classifying systems available, none encompass all the relevant issues.

Aims:

The purpose of this work is to present an all-inclusive and universally acceptable classification of the deformity which would graphically represent the entire gamut of possible presentations; principal and associated. Furthermore, based on such staging, the choice of surgical procedure and the stages of surgical intervention can be standardised to ensure the best results for the patient.

Patients and Methods:

This study is based on a series of 27 patients with a total of 38 cleft hands.

Results and Conclusions:

The necessity to include and to assess all determinants of function and complexity in these hands to standardise the choice of management, gave rise to the DAST system of classification; an acronym for all the morphological determinants of the anomaly (D = Digits missing, A = Associated anomalies in the hand, S = Site of cleft, T = Functional state of the Thumb). Numerical values were assigned to each component in increasing order of complexity. Score for each determinant as well as the aggregate score indicates the degree of complexity in a graphic manner. The DAST classification has a predictive value in choice of procedure and prognosticating surgical outcomes.

4q32-q35 and 6q16-q22 are valuable candidate regions for split hand/foot malformation

On the basis of the Human Cytogenetic Database, a computerized catalog of the clinical phenotypes associated with cytogenetically detectable human chromosome aberrations, we collected from the literature 102 cases with chromosomal aberrations and split hand/foot malformation or absent fingers/toes. Statistical analysis revealed a highly significant association (P<0.001) between the malformation and the chromosomal bands 4q32-q35, 5q15, 6q16-q22 and 7q11.2-q22 (SHFM1). Considering these findings, we suggest additional SHFM loci on chromosome 4q, 6q and probably 5q. The regions 4q and 6q have already been discussed in the literature as additional SHFM loci. We now show further evidence. In the proposed regions, there are interesting candidate genes such as, on 4q: HAND2, FGF2, LEF1 and BMPR1B; on 5q: MSX2, FLT4, PTX1 and PDLIM7; and on 6q: SNX3, GJA1, HEY2 and Tbx18.