Multiple ligation-dependent probe amplification (MLPA) analysis was performed using a SALSA MLPA P018-G1. Reference Kit (MRC-Holland, Amsterdam, The Netherlands) according to the manufacturerâ€™s instruction. The MLPA data analysis was performed using Coffalyser. To right Coffalyser sheet showing the ratios calculated for each probe. A value below 0.7 or above 1.3 is regarded as indicative of a heterozygous deletion (copy number change from two to one allele) or duplication (copy number change from two to three or more alleles), respectively. This kit contains probes for each exon of SHOX, as well as probes upstream and downstream of SHOX, where SHOX regulatory elements are located (CNE). Furthermore, several probes in the X-specific region of the X chromosome were included to characterize large deletions. Finally, nine autosomal reference probes were included for normalization.