TY - JOUR
T1 - Gain-of-function mutations in RPA1 cause a syndrome with short telomeres and somatic genetic rescue
AU - for the Undiagnosed Diseases Network
AU - Sharma, Richa
AU - Sahoo, Sushree S.
AU - Honda, Masayoshi
AU - Granger, Sophie L.
AU - Goodings, Charnise
AU - Sanchez, Louis
AU - Künstner, Axel
AU - Busch, Hauke
AU - Beier, Fabian
AU - Pruett-Miller, Shondra M.
AU - Valentine, Marcus B.
AU - Fernandez, Alfonso G.
AU - Chang, Ti Cheng
AU - Géli, Vincent
AU - Churikov, Dmitri
AU - Hirschi, Sandrine
AU - Pastor, Victor B.
AU - Boerries, Melanie
AU - Lauten, Melchior
AU - Kelaidi, Charikleia
AU - Cooper, Megan A.
AU - Nicholas, Sarah
AU - Rosenfeld, Jill A.
AU - Polychronopoulou, Sophia
AU - Kannengiesser, Caroline
AU - Saintomé, Carole
AU - Niemeyer, Charlotte M.
AU - Revy, Patrick
AU - Wold, Marc S.
AU - Spies, Maria
AU - Erlacher, Miriam
AU - Coulon, Stéphane
AU - Wlodarski, Marcin W.
N1 - Publisher Copyright:
© 2022 American Society of Hematology
PY - 2022/2/17
Y1 - 2022/2/17
N2 - Human telomere biology disorders (TBD)/short telomere syndromes (STS) are heterogeneous disorders caused by inherited loss-of-function mutations in telomere-associated genes. Here, we identify 3 germline heterozygous missense variants in the RPA1 gene in 4 unrelated probands presenting with short telomeres and varying clinical features of TBD/STS, including bone marrow failure, myelodysplastic syndrome, T- and B-cell lymphopenia, pulmonary fibrosis, or skin manifestations. All variants cluster to DNA-binding domain A of RPA1 protein. RPA1 is a single-strand DNA-binding protein required for DNA replication and repair and involved in telomere maintenance. We showed that RPA1E240K and RPA1V227A proteins exhibit increased binding to single-strand and telomeric DNA, implying a gain in DNA-binding function, whereas RPA1T270A has binding properties similar to wild-type protein. To study the mutational effect in a cellular system, CRISPR/Cas9 was used to knock-in the RPA1E240K mutation into healthy inducible pluripotent stem cells. This resulted in severe telomere shortening and impaired hematopoietic differentiation. Furthermore, in patients with RPA1E240K, we discovered somatic genetic rescue in hematopoietic cells due to an acquired truncating cis RPA1 mutation or a uniparental isodisomy 17p with loss of mutant allele, coinciding with stabilized blood counts. Using single-cell sequencing, the 2 somatic genetic rescue events were proven to be independently acquired in hematopoietic stem cells. In summary, we describe the first human disease caused by germline RPA1 variants in individuals with TBD/STS.
AB - Human telomere biology disorders (TBD)/short telomere syndromes (STS) are heterogeneous disorders caused by inherited loss-of-function mutations in telomere-associated genes. Here, we identify 3 germline heterozygous missense variants in the RPA1 gene in 4 unrelated probands presenting with short telomeres and varying clinical features of TBD/STS, including bone marrow failure, myelodysplastic syndrome, T- and B-cell lymphopenia, pulmonary fibrosis, or skin manifestations. All variants cluster to DNA-binding domain A of RPA1 protein. RPA1 is a single-strand DNA-binding protein required for DNA replication and repair and involved in telomere maintenance. We showed that RPA1E240K and RPA1V227A proteins exhibit increased binding to single-strand and telomeric DNA, implying a gain in DNA-binding function, whereas RPA1T270A has binding properties similar to wild-type protein. To study the mutational effect in a cellular system, CRISPR/Cas9 was used to knock-in the RPA1E240K mutation into healthy inducible pluripotent stem cells. This resulted in severe telomere shortening and impaired hematopoietic differentiation. Furthermore, in patients with RPA1E240K, we discovered somatic genetic rescue in hematopoietic cells due to an acquired truncating cis RPA1 mutation or a uniparental isodisomy 17p with loss of mutant allele, coinciding with stabilized blood counts. Using single-cell sequencing, the 2 somatic genetic rescue events were proven to be independently acquired in hematopoietic stem cells. In summary, we describe the first human disease caused by germline RPA1 variants in individuals with TBD/STS.
UR - http://www.scopus.com/inward/record.url?scp=85124601326&partnerID=8YFLogxK
U2 - 10.1182/blood.2021011980
DO - 10.1182/blood.2021011980
M3 - Article
C2 - 34767620
AN - SCOPUS:85124601326
SN - 0006-4971
VL - 139
SP - 1039
EP - 1051
JO - Blood
JF - Blood
IS - 7
ER -