The multi-locus systems (MLS) 33.15 and 33.6 (Jeffreys et al 1985a) and the single-locus systems (SLS) MS 1, MS 8, MS 31 and MS 43 (Wong et al. 1987) were investigated. The number of bands and the rate of band sharing were determined for both multi-locus systems and compared to the results of an English survey. Additionally 73 families were investigated using the multi-locus probes and the results compared to those obtained for the traditional blood grouping systems. The results were in full agreement so that no evidence of new mutations could be found. The fragment distribution was calculated for each of the 4 single-locus systems and compared to the values reported in an English survey (Smith et al. 1990b). Distinct discrepancies were seen in the systems MS 1 and MS 8. Family analyses were carried out for the 4 single-locus systems and compared to English data (Jeffreys et al. 1988) to look for any indications of possible new mutations. Only one isolated exclusion could be demonstrated with MS 1.