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Acute Myeloid Leukemia with Recurrent Genetic Abnormalities
Published in Wojciech Gorczyca, Atlas of Differential Diagnosis in Neoplastic Hematopathology, 2014
Abnormalities of chromosome 16 in AML have been associated with high complete remission and survival rates and favorable prognosis [43,49]. The t(16;16) or inv(16) results in the fusion of MYH11 at 16p13 with part of CBFB gene at 16q22. Additional karyotypic abnormalities may be present in up to 50% of AML patients with t(16;16)/inv(16) and most often include trisomies of chromosomes 8 (16%), 21, and 22 (22%) [50]. Majority of patients harbor at least one gene mutation, with RAS being affected in 53%, followed by KIT (37%) and FLT3 (17%; FLT3-TKD in 14% and FLT3-ITD in 5%) [50]. These additional karyotypic and/or molecular changes do not influence the achievement of complete remission. The overall outcome of patients having additional genetic changes was reported to be similar to patients with the sole chromosome 16 aberrations [43,51], but new data suggest that KIT mutation and trisomy 22 influence relapse-free survival and FLT3 mutation; trisomy 22, trisomy 8, and age- and t-AMLs influence overall survival [50]; trisomy 22 is associated with better prognosis; and FLT3 mutations and trisomy 8 are associated with worse prognosis. The coexistence of t(9;22) and inv(16) in CML appears to correlate with more rapid transformation into the blast phase (BP) [52]. Presence of del(7q) does not change the prognosis (including overall survival) in inv(16)+ AML.
Basic genetics and patterns of inheritance
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
In Robertsonian translocations, the satellites of two acrocentric chromosomes are lost and the q arms of the chromosomes fuse at the centromeres, resulting in a single chromosome (Fig. 12). Thus, a carrier of a Robertsonian translocation has a total of only 45 chromosomes, but has a balanced chromosome complement and is a normal individual. The loss of the satellites poses no problems since these regions of chromosome material encode repetitive sequences that are not essential. A Robertsonian translocation in a parent can result in an unbalanced chromosome abnormality in his or her offspring. If the zygote inherits the translocation chromo-some along with either one of the parents’ corresponding normal chromosomes, the child will have trisomy for that chromosome. If the zygote receives the translocation chromo-some alone, a normal carrier would be produced. If the zygote does not receive the translocation chromosome, and thus has one of the single involved chromosomes, a monosomy would be produced, which would cause a miscarriage. As previously discussed, most autosomal trisomies are lethal. The only unbalanced Robertsonian translocations seen in liveborn babies with trisomies are in Down syndrome and trisomy 13. Other trisomies for acrocentric autosomes, such as trisomy 14, trisomy 15, or trisomy 22 are lethal abnormalities and would cause miscarriages. The most frequent Robertsonian translocation encountered in the general population is a 13;14 translocation, followed in frequency by a 14;21 translocation (22). The former would place a carrier at high risk for having a child with trisomy 13, while the latter would result in a high risk for trisomy 21, and both would be expected to cause a higher risk for recurrent pregnancy loss due to lethal trisomies and monosomies.
Prenatal diagnosis of trisomy 22 at the first trimester of pregnancy
Published in Journal of Obstetrics and Gynaecology, 2020
Bi-Qiu Xu, Xiao-Cui Jiang, Li Wan, Sha Wang, Yan-Dong Yang, Dong-Zhi Li
Trisomy 22 is very rare in live-borns with a frequency of 1 in 30,000 to 50,000, but it is the second most common autosomal trisomy, after trisomy 16, present in miscarriages, accounting for 3% to 5% of all spontaneous abortions (Mokate et al. 2006). The few live-born infants have a very short life expectancy. Because of multiple malformations, prenatal diagnosis of trisomy 22 in the second or third trimester is easy and often follows an investigation for foetal growth restriction (FGR), with other structural abnormalities (Schwendemann et al. 2009). However, sonographic findings may not be remarkable in the first trimester. There has been a study which reported a distinctive pattern of first trimester maternal serum biochemical markers in trisomy 22 pregnancies (Sifakis et al. 2008). The present study presents a trisomy 22 pregnancy with a very high risk screening result for trisomy 21, which was not detected by matermal cell-free DNA (cfDNA) testing. It was picked up by a thorough first-trimester scan.
46,XX,der(9)t4;9)(q31.1;p24) as a novel genetic marker for spontaneous resolution of foetal pleural effusion
Published in Journal of Obstetrics and Gynaecology, 2018
E. H. Comert, E. S. Guvendag Guven, S. Guven, C. Kart, A. Cansu, A. Cebi
Gestational age at initial diagnosis is the main significant factor for prognosis. Serial ultrasonographic follow-up is suggested, if the foetus is not accompanied with hydrops or polyhydroamnios with pleural effusion under 34 weeks. Survival has been reported as 73–100% in cases with spontaneous resolution (Yinon et al. 2008). Yossi et al. defined togetherness of Down’s syndrome and congenital pleural effusion by the first time (Yoss and Lipsitz 1977). PPE is visible in syndromes of Turner and Noonan along with lymphatic malformations. Trisomy 22 was shown in cooperation with pleural effusion (Sepulveda et al. 2003). The 46% of cases in the literature placed the diagnosis before 30 weeks, bilateral in 58%, right isolated in 17%, isolated left pleural effusion in 24% of cases. Polyhydroamniosis was found in 42% of cases (Hagay et al. 1993).
Retrospective analysis of 4761 cases who underwent amniocentesis in southeast China
Published in Journal of Obstetrics and Gynaecology, 2018
Hehua Tao, Jianping Xiao, Canfeng Yang, Jun Wang, Ye Tang, Caiqin Guo, Junfeng Wang
Chromosomal abnormalities were found in 137 (2.88%) of 4761 patients (Table 2). Among these, there were 122 numerical chromosomal abnormalities and 15 structural chromosomal abnormalities. Among numerical chromosomal abnormalities, there were 72 trisomy 21 cases, 22 trisomy 18 cases, one trisomy 22 case, 16 sex chromosomal abnormalities and 11 rare mosaicism cases (Table 2). Polymorphic variants were detected in 5.97% (284/4761) patients. It is known that polymorphic variants are clinically insignificant heterochromatin areas that are not expected to have any phenotypic effects. The most frequently observed polymorphism was increase in heterochromatin region of the 1st chromosome, followed by a pericentric inversion on chromosome 9, which was similar to the findings of Ocak et al. (2014).