Duplication of chromosome 16p13.11-p12.3 with different expressions in the same family

The knowledge about genetic involvement in neurodevelopmental disorders, and especially in autism, is currently rising. To date, more than 100 gene mutations related to autistic syndromes have been described. Some disorders that affect multiple family members are caused by gene mutations, which can be inherited. Recently, array comparative genomic hybridization (aCGH) has identified sub microscopic deletions and duplications as a common cause of mental retardation and autism. In this article we report the occurrence of the same genetic finding (chromosome 16p13.11-p12.3 duplication) in a family with four small children, where two older siblings manifested a global neurodevelopmental delay associated with an autism spectrum disorder (ASD), but younger twin brothers with the same mutation, have typical development. Genetic analysis showed that the chromosomal duplication was inherited from the father, in which phenotype and functioning are quite typical. As is known, the duplication can pass from parents to children. The 16p13.11 micro duplication has been implicated in several neurodevelopmental and behavioral disorders and is characterized by variable expressivity and incomplete penetrance

THE INCIDENCE AND TYPE OF CHROMOSOMAL TRANSLOCATIONS FROM PRENATAL DIAGNOSIS OF 3800 PATIENTS IN THE REPUBLIC OF MACEDONIA

Robertsonian and reciprocal chromosomal translocations are the most frequent type of structural chromosomal aberrations in the human population. We report the frequency and type of detected translocations in 10 years of prenatal diagnosis of 3800 prenatal samples. The materials came from amniocentesis and chorionic villus samples (CVS). We detected seven Robertsonian translocations (0.18%), eight autosomal reciprocal translocations (0.21%) and one sex chromosome translocation (0.03%). The overall frequency of all translocations was 0.42%. Balanced state translocations were 0.29% and the frequency of translocations in an unbalanced state was 0.13%. There was one balanced de novo X-autosome translocation [46,X,t(X;10)(p11.23;q22.3)] and one balanced double translocation [46,XX,t(1;21);t(7;16)(1p21; 21q11) (7q31;16q23)] inherited from the mother. Most of the detected translocations were the result of unknown familial translocations, but some of them had been previously detected in one of the parents. In order to detect the recurrence risk for future pregnancies, we proposed genetic counseling in each of the cases and we established whether the parents were heterozygous for the same translocation. Histopatological findings for some unbalanced translocations correlated with phenotypes of detected unbalanced karyotype