PMC9682564_01
(A) HE images of the proband's pituitary adenoma (top) and her sister's pheochromocytoma (bottom). Images on the left were taken at lower (40X) magnification and those on the right at higher (100X) magnification. (B)
CHEK2 sequence traces from DNA obtained from the proband's pituitary adenoma (top) and the sister's pheochromocytoma(bottom), obtained from formalin-fixed paraffin embedded (FFPE) tissue, showing the presence of a frameshift variant (c.1000delC) and consistent with retention of both alleles or the presence of nontumoral admixed cells in the DNA. Reference wild-type sequence is shown for comparison.
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f1
She underwent a left adrenalectomy, and the pathology was consistent with a PCC ( Figure 1B ).
A pedigree chart of the affected family.
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f2
Due to patient's history of pituitary adenoma and PNET, she underwent genetic testing, which revealed CHEK2 c.1100delC, and no other susceptibility mutation was identified.  Figure 2  depicts her family pedigree, which shows both the patient and her younger sister have the CHEK2 mutation.
PMC9682564_02
(A) HE images of the proband's pituitary adenoma (top) and her sister's pheochromocytoma (bottom). Images on the left were taken at lower (40X) magnification and those on the right at higher (100X) magnification. (B)
CHEK2 sequence traces from DNA obtained from the proband's pituitary adenoma (top) and the sister's pheochromocytoma(bottom), obtained from formalin-fixed paraffin embedded (FFPE) tissue, showing the presence of a frameshift variant (c.1000delC) and consistent with retention of both alleles or the presence of nontumoral admixed cells in the DNA. Reference wild-type sequence is shown for comparison.
fendo-13-1024108-g001.jpg
PMC9682564_02_fendo-13-1024108-g001.jpg
f1
She underwent a left adrenalectomy, and the pathology was consistent with a PCC ( Figure 1B ).
(A) DNA sequence traces obtained from the individual clones carrying PCR fragments derived from the hPheo1 cell line derived from the proband's sister's pheochromocytoma tumor. Isolates carrying either a wild-type version (top) or the mutant version c.1100delC (bottom) of the CHEK2 gene were obtained. The position of the 1100C nucleotide is indicated by a red arrow. (B) Formalin-fixed paraffin-embedded tissue DNA from different slides was amplified for NF1 exon 32 and sequenced along with hPheo1 DNA (top). Additionally, PCR products were TA cloned and isolates sequenced (bottom). The position of the mutation is indicated (red arrow).
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f3
PCC, the CHEK2 locus was analyzed for the presence of c.1100delC using an allele-specific PCR assay using primers Chk2ex10f (5'-TTAATTTAAGCAAAATTAAATGTC), Chk2ex10r (5-GGCATGGTGGTGTGCATC), and Chk2delC (5'-TGGAGTGCCCAAAATCATA). PCR products were separated in 2-3% agarose gels, cloned, and sequencing was used to confirm this mutation ( Figure 3A ). Importantly, this analysis uncovered a pathogenic mutation in the NF1 gene, NM_001042492.3(NF1): c.4330A>G (p.Lys1444Glu) ( Figure 3B ), associated with predominance of the variant allele (MAF > 70%), and suggestive of loss of heterozygosity of the wild-type allele.