Expression of p63 protein in anaplastic large cell lymphoma: implications for genetic subtyping
HUMAN PATHOLOGY
Authors: Wang, Xueju; Boddicker, Rebecca L.; Dasari, Surendra; Sidhu, Jagmohan S.; Kadin, Marshall E.; Macon, William R.; Ansell, Stephen M.; Ketterling, Rhett P.; Rech, Karen L.; Feldman, Andrew L.
Abstract
Anaplastic large cell lymphomas (ALCLs) are CD30-positive T-cell non-Hodgkin lymphomas that bear chromosomal rearrangements of the TP53 homologue TP63 in a subset of cases that demonstrate aggressive clinical behavior. In the present study, we examined the relationship between p63 protein expression by immunohistochemistry and the results of fluorescence in situ hybridization using TP63 probes in 116 ALCLs. We also determined the relative expression of full-length TAp63 and truncated Delta Np63 isoforms (eg, p40) in ALCL cell lines and a subset of clinical cases. Overall, 35.3% of ALCLs were positive for p63 protein. Primary cutaneous and anaplastic lymphoma kinase negative ALCLs were positive more frequently than anaplastic lymphoma kinase positive ALCLs (P = .0034). As previously reported, cases with TP63 gene rearrangements expressed p63 uniformly. p63 expression in nonrearranged cases was associated with extra copies of TP63 on 3q28 (P < .0001). Extra copies of TP63 correlated with extra copies of the DUSP22 locus on 6p25.3 (P < .0001). Results of immunohistochemistry, Western blotting, and RNA sequencing indicated that p63 expression in nonrearranged cases was entirely attributable to TAp63 isoforms. Taken together, these findings indicate that ALCLs without TP63 rearrangements may express TAp63 isoforms of p63 and that this expression is associated with extra copies of TP63, probably due to widespread genomic copy number abnormalities rather than focal gains. Immunohistochemistry for p63 in ALCL is not specific for TP63 rearrangements but is useful clinically as a screening test to select cases for further testing by fluorescence in situ hybridization. Immunohistochemistry for Delta Np63 (p40) is not informative in the evaluation of ALCL. (C) 2017 Elsevier Inc. All rights reserved.
Novel heterozygous pathogenic variants in CHUK in a patient with AEC-like phenotype, immune deficiencies and 1q21.1 microdeletion syndrome: a case report
BMC MEDICAL GENETICS
Authors: Cadieux-Dion, Maxime; Safina, Nicole P.; Engleman, Kendra; Saunders, Carol; Repnikova, Elena; Raje, Nikita; Canty, Kristi; Farrow, Emily; Miller, Neil; Zellmer, Lee; Thiffault, Isabelle
Abstract
Background: Ectodermal dysplasias (ED) are a group of diseases that affects the development or function of the teeth, hair, nails and exocrine and sebaceous glands. One type of ED, ankyloblepharon-ectodermal defects-cleft lip/palate syndrome (AEC or Hay-Wells syndrome), is an autosomal dominant disease characterized by the presence of skin erosions affecting the palms, soles and scalp. Other clinical manifestations include ankyloblepharon filiforme adnatum, cleft lip, cleft palate, craniofacial abnormalities and ectodermal defects such as sparse wiry hair, nail changes, dental changes, and subjective hypohydrosis. Case presentation: We describe a patient presenting clinical features reminiscent of AEC syndrome in addition to recurrent infections suggestive of immune deficiency. Genetic testing for TP63, IRF6 and RIPK4 was negative. Microarray analysis revealed a 2 MB deletion on chromosome 1 (1q21.1q21.2). Clinical exome sequencing uncovered compound heterozygous variants in CHUK; a maternally-inherited frameshift variant (c.1365del, p.Arg457Aspfs*6) and a de novo missense variant (c.1388C > A, p.Thr463Lys) on the paternal allele. Conclusions: To our knowledge, this is the fourth family reported with CHUK-deficiency and the second patient with immune abnormalities. This is the first case of CHUK-deficiency with compound heterozygous pathogenic variants, including one variant that arose de novo. In comparison to cases found in the literature, this patient demonstrates a less severe phenotype than previously described.