Ring chromosomes are rare entities, usually associated with phenotypic abnormalities in correlation with the loss of genetic material. There are various breakpoints and sometimes there is a dynamic mosaicism that is reflected in clinical features. Most of the ring chromosomes are de novo occurrences. Our study reflects the experience of three Romanian cytogenetic laboratories in the field of ring chromosomes. We present six cases with ring chromosomes involving chromosomes 5, 13, 18, and 21. All ring chromosomes were identified after birth in children with plurimalformative syndromes. The ring chromosome was present in mosaic form in three cases, and this feature reflects the ring’s instability. In case of ring chromosome 5, we report a possible association with oculo-auriculo-vertebral spectrum.

Intellectual disability (ID) is a common disorder, with major consequences for individual

Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders that affect an individual's ability to communicate and socialize, often associated with repetitive movements or behaviors. Frequently patients associate intellectual disability or digestive problems. Autism is more common in males and affects 1 in 88 children in USA. The mechanism that leads to ASD is very complex, involving genetic, epigenetic, immune and environmental factors that could act in different proportions, at different developmental stages (prenatal, perinatal or postnatal) and on different pathways. The general prototype consists in an initial systemic dysfunction, such as immune dysregulation, inflammation, impaired detoxification or oxidative stress in an individual with genetic predisposition. In this context, ASD may arise due to the harmful action of environmental factors that lead to neuroinflammation and abnormal brain development. Environmental factors involved in autism determinism could be very diverse and include classical extrinsic factors (toxicants, environmental pollutants, medications, food additives, electromagnetic fields and even social influences), maternal disorders or lifestyle factors, as well as intrinsic factors (hormones, inflammatory mediators, microbiota and other biological molecules that make up the microenvironment around the developing fetal or neonatal brain). The aim of the present review is to discuss actual theories concerning genetic, epigenetic, immunologic and environmental factors interplay in ASD determinism, to present a practical and global approach of this complex problem, as well as to point some of the new directions for ASD prevention and therapy.

Duchenne and Becker muscular dystrophies (DMD/BMD) are X-linked progressive muscle disorders determined by mutations of the dystrophin (DMD) gene. Multiplex Ligation -Dependent Probe Amplification

We report a 20-year-old female with features evocative of Turner syndrome (short stature, broad trunk, mild webbed neck), dysmorphic face, minor features of holo-prosencephaly (HPE), small hands and feet, excessive hair growth on anterior trunk and intellectual disability. Cytogenetic analysis identified a pseudodicentric 14;18 chromosome. Genome wide single nucleotide polymorphism (SNP) array showed a terminal deletion of approximately 10.24 Mb, from 18p11.32 to 18p11.22, flanked by a duplication of approximately 1.15 Mb, from 18p11.22 to 18p11.21. In addition, the SNP array revealed a duplication of 516 kb in 16p11.2. We correlated the patient’s clinical findings with the features mentioned in the literature for these copy number variations. This case study shows the importance of microarray analysis in the detection of cryptic chromosomal rearrangements in patients with intellectual disability and multiple congenital anomalies.