Trisomy 13 with a 13q14q translocation.

A sporadic case of Patau syndrome with 46,XY,14-,t(13q14q)+ karyotype is reported in a 2-month-old child. Dermatoglyphic and cytogenetic findings of the propositus and cytogenetic study of his parents are presented.     

A homologous tandem translocation [45,XX,-13,-13,+t(13;13) (q12;q34)

Chromosomal investigation of a young girl with mental and motor retardation and congenital anomalies revealed a translocation between both members of pair No. 13. Banding analysis showed that the translocation was "tandem," leading to monosomy for segments in both the long and short arms of No. 13.     

Interstitial deletion of chromosome 13 involving the region 13q14

Summary A patient with an interstitial deletion 13q14 is described who has decreased erythrocyte esterase D activity and who has not developed a retinoblastoma.     

Partial trisomy 14q and familial translocation (2;14) (q12;q13).

A female patient with moderate psychomotor retardation, minor anomalies and proximal trisomy 14q due to segregation of a maternal translocation is reported.     

A 45,XX,-5,-14,+t(5q;14q)mat cri du chat child.

A two-year-old girl has the following features of the cri du chat syndrome: microcephaly, hypertelorism, downward slanting of the palpebral fissures, psychomotor retardation and a cat-like cry. She is only of five patients having the cat cry syndrome with 45 chromosomes. Her karyotype is 45,XX, -5, -14, +t(5; 14)(5qter leads to 5p11: : 14q11 leads to 14qter) with the translocation inherited from her mother and maternal grandmother, each of whom is the carrier of a balanced translocation 46,XX,t(5;14)(p11q11). Normal plasma activity for hexosaminidase B suggests the locus for this enzyme is not located in the delected segment of 5 p.     

Four novel Loci (19q13, 6q24, 12q24, and 5q14) influence the microcirculation in vivo

There is increasing evidence that the microcirculation plays an important role in the pathogenesis of cardiovascular diseases. Changes in retinal vascular caliber reflect early microvascular disease and predict incident cardiovascular events. We performed a genome-wide association study to identify genetic variants associated with retinal vascular caliber. We analyzed data from four population-based discovery cohorts with 15,358 unrelated Caucasian individuals, who are members of the Cohort for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium, and replicated findings in four independent Caucasian cohorts (n = 6,652). All participants had retinal photography and retinal arteriolar and venular caliber measured from computer software. In the discovery cohorts, 179 single nucleotide polymorphisms (SNP) spread across five loci were significantly associated (p<5.0×10(-8)) with retinal venular caliber, but none showed association with arteriolar caliber. Collectively, these five loci explain 1.0%-3.2% of the variation in retinal venular caliber. Four out of these five loci were confirmed in independent replication samples. In the combined analyses, the top SNPs at each locus were: rs2287921 (19q13; p = 1.61×10(-25), within the RASIP1 locus), rs225717 (6q24; p?=?1.25×10(-16), adjacent to the VTA1 and NMBR loci), rs10774625 (12q24; p = 2.15×10(-13), in the region of ATXN2,SH2B3 and PTPN11 loci), and rs17421627 (5q14; p?=?7.32×10(-16), adjacent to the MEF2C locus). In two independent samples, locus 12q24 was also associated with coronary heart disease and hypertension. Our population-based genome-wide association study demonstrates four novel loci associated with retinal venular caliber, an endophenotype of the microcirculation associated with clinical cardiovascular disease. These data provide further insights into the contribution and biological mechanisms of microcirculatory changes that underlie cardiovascular disease.     

Human inner ear OCP2 cDNA maps to 5q22-5q35.2 with related sequences on chromosomes 4p16.2-4p14, 5p13-5q22, 7pter-q22, 10 and 12p13-12qter

Mouse Ocp2-rs2 maps to chromosome 11 and encodes an 18.6 kDa peptide abundantly expressed in the organ of Corti. We show that sequences similar to murine Ocp2-rs2 are found on human chromosomes 4p16.2-4p14, 5p13-5q35.2, 7pter-q22, 10 and 12p13-12qter as revealed by Southern blot analyses of human/rodent somatic cell hybrids. A fetal human inner ear cDNA library was screened with a cloned 254 bp PCR product of murine Ocp2-rs2. One of two human cDNA clones (CM1) was sequenced from the 5′ end that begins with murine Ocp2-rs2 codon 14 through the stop codon and 258 nucleotides of 3′-UTR and was found to have the identical deduced amino acid sequence to Ocp2-rs2. Based on the sequence in the 3′-UTR of CM1, a PCR primer pair was synthesized and used to confirm that a human homologue of Ocp2-rs2, designated OCP2 and expressed in the developing human inner ear, is localized to 5q22-5q35.2. Other OCP2-like sequences located on chromosomes 4p16.2-4p14, 7pter-q22 and 12p13-12qter (but not the chromosome 10 OCP2-like sequence) will PCR amplify the expected size product at a lower annealing temperature using the OCP2 3′-UTR PCR primers indicating that there may be a human OCP2 gene family.     

Unusual findings by fluorescence microscopy of a t(13q14q)

Summary Fluorescence studies in a 13q14q translocation seem to indicate, that the centromeric region of both chromosomes has been preserved. It is assumed, that the 13 centromere, not visible in Giemsa staining, is suppressed by the active 14 centromere. It is emphasized that Robertsonian translocations in man might be due to breaks in the short arms of the involved chromosomes.

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Zusammenfassung Die Färbung einer 13q14q-Translokation mit Quinacrin-Lost scheint zu indicieren, daß die Zentromerregionen beider Chromosomen erhalten sind. Das Zentromer des Chromosoms Nr. 13 ist nicht sichtbar bei Giemsafärbung. Es ist möglich, daß es durch das aktive 14-Zentromer unterdrückt worden ist. Zentrische Fusionen beim Menschen können somit wahrscheinlich durch Brüche an beiden kurzen Armen der implizierten Chromosomen entstehen.

     

A child with mosaicism for deletion (14)(q11.2q13)

In this case report we describe a child with a de novo deletion in the (q11.2q13) region of chromosome 14. The child presented with dysmorphic features - anophthalmia, microcephaly, and growth retardation. Cytogenetic studies showed mosaicism. The karyotype was 46,XX,del(14)(q11.2;q13) [16] /46,XX [9]. We compared the features observed in this child with that of others with the same deletion reported in scientific literature and found that this is the first report of a child mosaic for this deletion. It is also the first time it has been reported in association with anophthalmia.     

Complex chromosomal rearrangement involving chromosomes 11, 13, 14 and 18 resulting in monosomy for 13q32----qter

A five-year-old boy with speech delay, minor facial abnormalities and borderline psychomotor retardation was found to have a complex de novo double translocation involving four chromosomes resulting in monosomy for the segment 13q32----qter. Chromosomes involved were 11, 13, 14, and 18. The translocation between chromosome 11 and 13 was unbalanced with the loss of the segment 13q32----qter. The second translocation between 14 and 18 was apparently balanced.     

Inherited pericentric inversion of chromosome no. 2 with Robertsonian translocation (13q 14q) resulting in trisomy for chromosome 13q

This report includes a patient with an inherited pericentric inversion of chromosome No. 2 in addition to a Robertsonian translocation resulting in trisomy for chromosome 13q. The chromosomal constitution of the proband was 46,XX,inv(2) (pter leads to p11 : : q14 leads to p11 : : q14 leads to qter); t(13,14) (13qter leads to 13p11 : : 14q11 leads to 14qter). Sequential QFQ, RFA and GTG banding techniques were employed on the chromosomes of all family members. The chromosomal constitutions of the father and his first child were normal while the mother had an inversion of chromosome No. 2 [46,XX,inv(2) (pter leads to p11 : : q14 leads to p11 : : q14 leads to qter)]. The proband inherited this abnormal chromosome. In addition, she had a de novo Robertsonian translocation involving chromosomes 13q and 14q resulting in trisomy of chromosome 13q.     

Meiotic segregation of chromosomes 13 and 14 in sperm of heterozygous Robertsonian translocation der(13;14)(q10;q10) carriers

Meiotic segregation of chromosomes 13 and 14 was assessed by fluorescence in situ hybridization on sperm of five heterozygous carriers of the most frequent Robertsonian translocation der(13;14). Alternate segregation mode was predominant (mean 78.2 ± 5.7%). The prevalence of balanced sperm varied from 69.4 to 86.5%. Adjacent segregation mode was detected in 18.64 ± 4.90% of sperm; 3:0 mode was detected in 2.48 ± 1.20% of sperm. These results are informative for reproductive counseling of Robertsonian translocation der(13;14) carriers providing information for assessment of probability of receiving normal/balanced embryos in assisted reproduction cycles.