Molecular genetic demonstration of the diverse evolution of Richter's syndrome (chronic lymphocytic leukemia and subsequent large cell lymphoma)

Paired samples of chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) and the subsequent diffuse large cell lymphoma (DLL) of six cases of Richter's syndrome were investigated to establish the clonal relationship between the CLL/SLL and the DLL components and to define the oncogene and/or tumor-suppressor gene alterations involved in the morphologic transformation of CLL/SLL. Southern blot hybridization analysis showed identical clonal immunoglobulin (Ig) gene-rearrangement patterns in the CLL/SLL and DLL components in four cases and different Ig gene-rearrangement patterns in two cases. Polymerase chain reaction (PCR) amplification, cloning, and DNA sequencing of complementary determinant region 3 (CDR3) of the Ig-heavy chain gene of one of the two cases in which the Ig gene- rearrangement patterns were different showed nonidentical sequences in the CLL/SLL and DLL components. In the other case, monomorphic Epstein- Barr virus (EBV) genome integration was detected in the DLL but not in the CLL, suggesting that the CLL and DLL components in this case of Richter's syndrome also represent unrelated clones. Single-strand conformation polymorphism (SSCP) analysis and sequencing of exons 5 through 9 of the p53 tumor-suppressor gene showed a mutation in codon 176 of the DLL but not in the CLL/SLL component in one case where the CLL/SLL and DLL represented different clones. The p53 mutation probably played a role in the development of the lymphoma rather than morphologic transformation of the CLL/SLL in this case. SSCP analysis and sequencing also showed identical mutations in codon 282 in both the CLL/SLL and DLL components in a case where the CLL and DLL represented identical clones. Thus, this p53 gene mutation was present both before and after morphologic transformation, and therefore, probably did not play a primary role in this process. Southern blot hybridization analysis failed to show evidence of bcl-1, bcl-2, c-myc proto-oncogene or retinoblastoma (Rb) tumor-suppressor gene rearrangements in these six cases of Richter's syndrome. In conclusion, the original CLL/SLL and the subsequent DLL in Richter's syndrome may or may not be derived from identical clones, and the well-known proto-oncogenes and tumor- suppressor genes do not appear to play an obvious and consistent role in the morphologic transformation of CLL/SLL to DLL.     

Detection and Characterization of a De Novo Alu Retrotransposition Event Causing NKX2-1-Related Disorder

Background

Heterozygous NKX2-1 loss-of-function variants cause combinations of hyperkinetic movement disorders (MDs, particularly childhood-onset chorea), pulmonary dysfunction, and hypothyroidism. Mobile element insertions (MEIs) are potential disease-causing structural variants whose detection in routine diagnostics remains challenging.

Objective

To establish the molecular diagnosis of two first-degree relatives with clinically suspected NKX2-1-related disorder who had negative NKX2-1 Sanger (SS), whole-exome (WES), and whole-genome (WGS) sequencing.

Methods

The proband's WES was analyzed for MEIs. A candidate MEI in NKX2-1 underwent optimized SS after plasmid cloning. Functional studies exploring NKX2-1 haploinsufficiency at RNA and protein levels were performed.

Results

A 347-bp AluYa5 insertion with a 65-bp poly-A tail followed by a 16-bp duplication of the pre-insertion wild-type sequence in exon 3 of NKX2-1 (ENST00000354822.7:c.556_557insAlu541_556dup) segregated with the disease phenotype.

Conclusions

We identified a de novo exonic AluYa5 insertion causing NKX2-1-related disorder in SS/WES/WGS-negative cases, suggesting that MEI analysis of short-read sequencing data or targeted long-read sequencing could unmask the molecular diagnosis of unsolved MD cases. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.     

Breast specimen radiography: evaluation of a compression device

The irregular shape and uneven tissue thickness of excised breast specimens makes radiographic evaluation difficult, especially when calcifications are not present. Xeroradiographs before and after compression of 20 separate excised breast specimens were compared, and 17 of the same specimens were compared after compression combined with immersion in water. Specimen compression improved visibility of the lesion on average in 88% of cases, and visibility was equal in 12%. Combined compression/immersion further improved visibility of the lesion on average in 37% of cases. More significantly, evaluation of the compressed specimen led to a change in interpretation of the radiographs in 45% of cases. Compression of the specimen in specimen radiography is recommended in all cases in which pre-biopsy localization is performed.     

Speech-controlled generation of radiology reports

Voice entry has been successfully employed to generate radiology reports with a word recognizer with a 1,000-word lexicon capacity. About 50% of reports were able to be dictated with a single 900-word lexicon. This was split into five sections by anatomic or subspecialty application. Each was augmented to 900 words. By switching from one lexicon to another, it was possible to dictate more than 70% of reports. With exclusive use of three lexicons in subspecialty areas (gastrointestinal radiology, neuroradiology, and mammography), and with further modification of the respective vocabulary, it has been possible to employ the system 88% of the time. Twelve percent of cases included wording that was beyond the scope of the lexicon. Computer subsets that allow different translations of some words when used in different contexts have been used. Some of these are used as triggers that will print whole lines, sentences, or even complete reports. Dictation times with voice entry take about 20% longer. Recognition reliability has been greater than 95%.