Trisomy 5:A Rare Isolated Finding in Pediatric B-lymphoblastic Leukemia

Background and Objectives: In acute leukemia, all diagnostic criteria and treatment protocols are based on cytogenetic and molecular geneticfindings. Despite recent advances in molecular biology, cytogenetic studies still play a pivotal role in the sub-classification of B-lymphoblastic leukemia (B-ALL). B-ALL is characterized by clonal cytogenetic abnormalities with numerical chromosomal aberrations being more common. An extra copy of chromosome 5 is common to see in cases with hyper diploidy. However, a gain of chromosome 5 as a sole anomaly is exceptionally rare in B-ALL. To date, trisomy 5 as a sole abnormality is reported in few cases only. We aimed to report the clinicopathologic profile of this rare finding to increase knowledge and highlight the disease course of these patients.Methods: We report a case of a 14-year boy presented with fever, lethargy and episodes of nasal bleeding for two weeks. He was admitted to the pediatric oncology unit at Indus hospital and health network, Karachi. Flowcytometry performed on peripheral blood using 8-color flowcytometry. Conventional karyotyping was performed by GTG banding. FISH panel was comprisedof dual color dual fusion probes for BCR::ABL1and ETV6::RUNX1whereas break apart probe for KMT2A (Metasystem, Germany).Digital image analysis for karyotyping and FISH was done on Leica Biosystems, Cytovision MB8.Results:Flowcytometry results were consistent with B-ALL. Cytogenetic analysis on his bone marrow aspirate revealed trisomy 5 as a sole abnormality with no evidence of any other clonal cytogenetic abnormality. FISH studies for BCR::ABL1, ETV6::RUNX1and KMT2Ashowed no evidence of gene rearrangements.Conclusion:Trisomy 5 is a very rare cytogenetic aberration. Only few cases reported in children. Inferior outcome is reported in both children and adults. The increasing number of reported cases raises the possibility of a distinct cytogenetic entity. Its prognostic and therapeutic implications are yet to be explored.

A Case of Pediatric Acute Lymphoblastic Leukemia with Trisomy 5 as a Sole Chromosomal Anomaly: A Prognostic Significance / 임상소아혈액종양

We present a case of Korean pediatric patient with pre-B cell type acute lymphoblastic leukemia (ALL) with trisomy 5 as a sole cytogenetic anomaly. Here, we compare and describe the present case with previous pediatric case reports and provide a review of the literature. This case report may help elucidate the poor prognostic impact of trisomy 5 as a sole cytogenetic anomaly in pediatric patients with ALL. Additional studies are needed to confirm this hypothesis.

Cytogenetic and clinical analysis of a patient with partial trisomy 5p / 国际检验医学杂志

Objective To further explore the relationship between increasing genetic material and clinical manifestation of partial trisomy 5p .Methods G‐banding karyotypes of peripheral blood lymphocytes in the patient and his parents ,and at the same time to summary the partial trisomy 5p clinical performance .Results patient ,46 ,XX ,der(6)t(5 ;6)(p13;q25) mat ;partial trisomy for 5p13→pter resulting from the balanced translocation of the mother .Mother:46 ,XX ,t(5;6)(p13 ;q25);carrier of a balanced 5/6 translocation .Father :46 ,XY .Conclusion The phenotype of trisomy 5p may be associated with express and function of gene at spe‐cial chromosome region .

Prenatally Diagnosed Uncommon Mosaic Autosomal Trisomy

Prenatal diagnosis of rare autosome mosaicism involvingchromosomes other than chromosome 13, 18, 21 or the sex chromosome is encountered prognostic dilemma during genetic counseling. We report four cases of level III uncommon mosaicism of trisomy 5, 16 and 20,diagnosed prenatally. In case 1 with mosaic trisomy 20, there was a higher mosaic ratio of trisomy 20 in the repeat amniocentesis (62.1%) than in the first (36.6%) with normal fetal ultrasound finding except for a relatively small aorta on a 3-vessel view of the fetal heart. Case 2 showed a low rate of mosaic trisomy 20 (5.25%) in cultured amniocytes but normal karyotype in the repeat amniocentesis, who delivered a normal healthy baby. Case 3 showed a 13.6% of trisomy 16 mosaicism in the 30 cells of cultured amniocytes. Sixty cells from a fetal blood sample at termination showed non-mosaic 46,XX normal karyotype, while skin fibroblasts had 22.5% trisomy 16 in 40 metaphases. The autopsy showed ventricular septal defect (VSD). Case 4 with low grade mosaicism (10.5%) of trisomy 5 resulted in elective termination, though the ultrasoumd showed growsly normal fetus. Although level III mosaicism is regarded as true mosaicism, it is difficult to predict the outcome of the fetus with rare mosaic autosome trisomy. Therefore mosaic autosome trisomy of fetus should be carefully interpreted with more various approaches including repeat sampling and targeted fetal ultrasound.

A De Novo Unbalanced Translocation t (5;7) (q33;p22) Carrying Partial Trisomy 5q and Partial Monosomy 7p / 대한임상병리학회지

Partial trisomy of the long arm of chromosome 5 distal to 5q33 is rare. Only 16 cases have so far been reported. We report on a three-year-old boy with microcephaly, growth and developmental delay, mild mental retardation, and facial dysmorphism caused by partial 5q trisomy and partial 7p monosomy. The patient has an apparently unbalanced translocation resulting from a rearrangement between chromosomes 5 and 7 (46,XY,der (7)t (5;7) (q33;p22)de novo). Fluorescence in situ hybridization with chromosome 5 and 7 painting probes and a cri-du-chat critical region probe confirmed this chromosome rearrangement. Most cases of partial trisomy 5q33-q35 described to date are due to the unbalanced transmission of a familial translocation. To the best of our knowledge, there are no previous reports of de novo unbalanced translocations of these two chromosome abnormalities together with similar breakpoints.

An unusual combination of trisomy 21 and partial trisomy 5q

The authors describe a male newborn with multiple congenital anomalies; craniofacial dysmorphism, bilateral cleft palate and lip, ambiguous external genitalia with absence of phallus, ventricular septal defect, agenesis of olfactory bulbs, and presence of small round cells simulating migration defect in the cerebellar white matter. Cytogenetic study demonstrated a chromosomal constitution of 47,XY, +21, +5q. Its pathological significance compared with Down's syndrome and hitherto reported partial trisomy 5q is discussed.