MONOSOMY-6Q - REPORT ON 4 NEW CASES

We report on four patients with partial monosomy of the long arm of ch romosome 6: two children presenting with an interstitial deletion del( 6)(q14q16), the two others presenting with a terminal deletion del(6)( q25qter). These patients are compared with previous reports in the lit erature: 16 cases of terminal deletion and 17 cases of interstitial de letion. The deletions most often occur de novo. Mental retardation is always described. Dysmorphic facial features range between minor and m ajor. There may be associated visceral abnormalities. After comparing the size and the localisation of the deletions with clinical data, we are now able to suggest a clinical localisation on chromosome 6.