An eight-case 1q21 region series: novel aberrations and clinical variability with new features.

BACKGROUND: Rearrangement of the 1q21 region of chromosome 1 manifests as multiple phenotypes, including microcephaly, intellectual disability, dysmorphic facial features, eye abnormalities, cardiac defects, genitourinary anomalies, autism spectrum disorder, psychiatric conditions and seizures. Herein, we describe eight patients with 1q21 deletion and duplication syndromes, and novel deletions and findings. METHODS: Chromosomal microarray analysis was performed to identify the existence of copy number variation. Quantitative polymerase chain reaction was applied using specific primers for the control and 1q21 region of chromosome 1. Mutational analysis was performed in case 5 using direct genomic sequencing for exons 1-6 in RBM8A. RESULTS: Copy number variation analysis identified seven deletions and one duplication of the 1q21 region in the eight patients. In addition, four variations were de novo, and two deletions are reported here for the first time. One of the cases (case 7) presents moderate intellectual disability and dysmorphic facial findings, whereas chromosomal microarray analysis showed that case 7 had an 889-kb deletion in the 1q21 proximal region (GPR89A, PDZK1, CD160, POLR3C and NBPF12). CONCLUSION: Although the deletion in case 5 did not include the thrombocytopenia-absent radius syndrome critical region or the RBM8A gene, he had pectoral muscle hypoplasia, radius and humerus hypoplasia and short curved ribs, which are indicative of a potential thrombocytopenia-absent radius region modifier. The findings in case 7 suggest that the proximal part of the 1q21 microdeletion syndrome region might be very important for the onset of clinical manifestations. Some novel findings were observed in the presented cases, such as radius and humerus hypoplasia and brain stem hypoplasia. The presented findings expand the spectrum of 1q21 aberrations and provide evidence of genotype-phenotype correlations for this region.

Mitochondrial DNA copy number alterations in familial mediterranean fever patients.

OBJECTIVES AND BACKGROUND: Familial Mediterranean Fever (FMF) is characterized by recurrent fever episodes as a result of inflammation of serous membranes. Changes in the number of different mtDNA copy number variations, detected in FMF patients, who developed amyloidosis, might be an important parameter in the understanding of the pathophysiology of the disease. METHODS: Changes in the mtDNA copy number between 50 patients with FMF, who had M694V homozygote mutation and amyloidosis, and 50 healthy controls, who had not any MEFV mutation or FMF clinical finding, were examined. The 22 MEFV mutations were analyzed by Pyromark Q24 system. Quantitative analysis was performed on RT-PCR. The level of mtDNA was calculated using the delta Ct (ΔCt) of average Ct of mtDNA and nDNA (ΔCt = Ct mtDNA-Ct nDNA) in the same well as an exponent of 2 (2ΔCt). RESULTS: A significant decrease in the amount of mtDNA was detected in FMF patients with M694V homozygous mutation carriers, who developed amyloidosis compared to the control group (p < 0.001). CONCLUSION: In this study, mitochondrial dysfunction, which has been identified through changes in the mitochondrial genome in many diseases, was identified by showing that the copy number variations of mtDNA in leukocytes also decreased for FMF disease (Tab. 3, Fig. 1, Ref. 21).

PARTIAL TRISOMY 5p12-q 11.2 RESULTING FROM A MARKER CHROMOSOME: A NEW CASE REPORT WITH ATTENTION DEFICIT HYPERACTIVITY DISORDER.

Partial trisomy of chromosome 5 was first described by Lejeune et al. in 1964 on the short arm (12). The vast majority of the partial trisomy 5 cases include 5p duplications; however we reported a small supernumerary marker chromosome. General symptoms include developmental delay, mental retardation, seizures, respiratory difficulties, congenital heart defects, abdominal muscle hypoplasia and dysmorphic features such as macrocephaly, enlarged anterior fontanelle, dolichocephaly, upslanting palpebral fissures, epicanthal folds, hypertelorism, abnormal ears, midface hypoplasia, short nose, broad nasal bridge and microretrognathia. Arachnodactyly and club foot may be seen as cytoskeletal abnormalities and, hypotonia may be determined in neurological exam. Here we reported a case with developmental delay, attention deficit hyperactivity disorder, mild mental retardation and dysmorphic features, caused by a new small supernumerary marker chromosome, generating partial trisomy 5pI 2-q 11.2. To our knowledge, this small supernumerary marker chromosome has not been reported before. Severe type of partial trisomy 5 includes seizures, congenital heart defects, hypotonia and failure to thrive. Previously reported partial trisomy 5 cases, who showed severe phenotype, had usually duplicated 5p13 region. Therefore, patients, who do not have duplicated 5p13, showed mild phenotype. Also, duplication of the long arm of chromosome 5, may contribute to the milder phenotype and the longer survival in partial trisomy 5 patients. Attention deficit hyperactivity disorder, which we described in the present case, may be a result of partial trisomy 5, because it includes ADHD4 gene. This case may help better understanding the karyotype/phenotype correlation related to partial trisomy 5.