Abstract 3118
Background
Retinoblastoma (RB) is the most common pediatric intraocular neoplasm caused by the biallelic inactivation of the RB1 tumor suppressor gene. In 40% of cases, the development of RB is mediated by a germline mutation in one of the alleles of RB1. Patients with germline mutation develop bilateral tumor with penetrance of more than 90%. However, some families demonstrate cases of RB with low penetrance (unaffected carries) and variable expressivity (carries develop either bi- or uni- RB).
It is believed that the phenotypic manifestation of hereditary retinoblastoma depends on the functional type of the germinal mutation in the RB1. The molecular mechanisms underlying the variable phenotypic manifestation of the same mutation in different family members are currently explained by the parent-of-origin effect of RB1 mutation.
Methods
Using NGS of the RB1 we have analyzed DNA from blood of 331 unrelated patients with RB (226 patients with uni- RB and 105 with bi- RB). DNA samples of available family members were also examined for the presence of an identified mutation using Sanger sequencing.
Results
We identified 11 germline mutations in the RB1 that led to the RB with low penetrance and/or variable expressivity in 12 families. Among the identified mutations:, 25.0% - are missense mutations, 58.3% - are splice mutations and 16.7% - are frame shift mutations. In 91,7% of cases, probands inherited the mutant allele from their fathers, who were either clinically healthy carriers (7 families) or had the uni-/bilateral form of RB (3 families).Table: 1170P
Mutations | Carrier (Proband, P) | Form (uni, U; bi-lateral, B; no symptoms, -) |
---|---|---|
c.1364G>C; c.1573G>A; c.1981C>T; с.607 + 1G-T (2 families); c.45_76del; с.83del | P ♂ | U - |
c.861G>C | P ♀ | U - |
c.939G>A | P ♂ Grandfather Uncle | U - - U |
c.380 + 1G-A; с.1695 + 5G-T; c.1696-2A-G | P ♂ | B U |
Conclusions
The identification of mutations in the RB1 leading to the development of RB with low penetrance and variable expressivity, is necessary for adequate treatment and competent determination of the risk of developing the disease in other family members.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
State assignment of Ministry of Science and Higher Education of the Russian Federation.
Funding
The state assignment of Ministry of Science and Higher Education of the Russian Federation.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
2115 - Preclinical in vivo screening to predict responder patients depend on EGFR status
Presenter: Yejin Kim
Session: Poster Display session 3
Resources:
Abstract
3349 - Interplay between miR-17-5p and MALAT-1 Shapes The Cytokine Storm in Triple Negative Breast Cancer (TNBC) Tumor Microenvironment
Presenter: Raghda Soliman
Session: Poster Display session 3
Resources:
Abstract
4014 - Clinical verification on the relationship between lipid metabolism and the immune microenvironment of breast cancer
Presenter: Wataru Goto
Session: Poster Display session 3
Resources:
Abstract
4158 - The clinical and transcriptional signatures of human CD204 reveal an applicable marker for tumor associated macrophage in breast cancer
Presenter: Yunjie He
Session: Poster Display session 3
Resources:
Abstract
5392 - Activated effector T cells co-expressing multiple inhibitory receptors (IRs) are enriched in the tumor immune microenvironment in high grade serous ovarian cancer (HGSOC)
Presenter: Alice Bergamini
Session: Poster Display session 3
Resources:
Abstract
2617 - Oncolytic reovirus as a new anti-tumor strategy in castration resistant prostate cancer
Presenter: Yunlim Kim
Session: Poster Display session 3
Resources:
Abstract
2995 - Dysregulation of helper T lymphocytes in esophageal squamous cell carcinoma (ESCC) patients is highly associated with aberrant production of miR-21
Presenter: Ali Memarian
Session: Poster Display session 3
Resources:
Abstract
3597 - Myeloid derived suppressor cells but not regulatory T cells are associated with adaptive immunity and clinical outcomes in anal squamous cell carcinoma
Presenter: Christophe Borg
Session: Poster Display session 3
Resources:
Abstract
3430 - Evaluation of immune responses among responders (R) and non-responders (non-R) in a humanized mouse model with colorectal cancer (CRC) xenografts treated with combination immunotherapy
Presenter: Juan Marín Jiménez
Session: Poster Display session 3
Resources:
Abstract
1995 - ¬¬Advanced melanoma patients with high CD16+ macrophages have better response and survival to anti-PD-1 based immunotherapy
Presenter: Hansol Lee
Session: Poster Display session 3
Resources:
Abstract