Patient with syndromic cleft lip-palate, mosaic karyotype and cytogenetically abnormal brother

Department of Human and Medical Genetics, Faculty of Medicine, Vilnius University, Santariškių 2, LT-08661 Vilnius, Lithuania Objective. Cleft lip with or without cleft palate (CLP) is a common congenital abnormality involving genetic and non-genetic factors in its etiology. Although many studies have been made to find the genetic pattern of this malformation, there is still no precise answer. There have been suggested several models of inheritance where a few major loci are influenced by the number of modifiers. The number of modifiers is still unknown and could be scattered all over the genome. Chromosome rearrangements are one of the tools that can help to trace these genes. Materials and methods. Patient blood samples for cytogenetic analysis were collected. Karyotyping and comparative genomic hybridization analysis was performed according to standard protocols. Results. The karyotype of the patients was found to consist of 4 different cell clones involving rearrangements of chromosome 21. The patient phenotype involved various congenital abnormalities including cleft lip palate. Chromosome 21 abnormality was detected using both methods. The parents’ karyotype was normal, while the brother had karyotype 47, XYY. Conclusions. Altered chromosome region on chromosome 21 is large enough to involve several dozens of genes. We predict that one or even a few of them could be involved in orofacial morphogenesis, at least as modifiers.