Secondary hemophagocytic lymphohystiocytosis in a Rubinstein Taybi syndrome patient

Oral and cephalometric study in Brazilian Rubinstein–Taybi syndrome patients

“…All 13 patients exhibited broad thumbs. Children with RSTS seem to have an increased risk of benign and malignant tumors 5 . None of this study's patients showed any tumor until the end of this study period.…”

“…CBP is a transcriptional coactivator that plays an essential role in chromatin remodeling, signaling pathways, and basic cellular functions, such as DNA repair, cell growth, differentiation, and tumor suppression. Both CBP and p300, a highly related and widely expressed protein, are crucial for healthy embryonic development 1–3,5 . Genetic tests are helpful in diagnosing RSTS, but most cases are currently diagnosed based on clinical features 2,6 …”

Identical EP300 variant leading to Rubinstein–Taybi syndrome with different clinical and immunologic phenotype

“…P1 suffers from profound combined immunodeficiency, as defined by recurrent and severe infections, failure to thrive, splenomegaly, reduced vaccine responses, early onset of multiple cytopenia (recurrent episodes of autoimmune hemolytic anemia, intermittent neutropenia, and thrombocytopenia), severe lymphopenia (0.5–0.8 lymphocytes × 10 9 /L, associated with an increased proportion of T‐ and B‐ cell subsets such as CD3 + CD4 − CD8 − αβ + and CD19 hi CD21 lo ), hypgammaglobulinemia (IgG: <400 mg/dl, IgA: 1 mg/dl, and IgM: 50 mg/dl), and reduced T‐lymphocyte proliferation to mitogens and specific T‐cell stimuli. He was treated with steroids and high dose immunoglobulin when cytopenia occurred, sirolimus to control splenomegaly, trimethoprim sulfametoxazole prophylaxis due to lymphopenia (Saettini et al, 2018), and acyclovir due to HSV‐1 reactivation in the setting of secondary hemophagocytic lymphohystiocytosis (Saettini et al, 2021). On the contrary, P2 did not experience any type of infections and did not require any infection prophylaxis.…”

“…B cell defects, mostly resulting in hypogammaglobulinemia and/or impaired vaccine response, have been reported in RSTS patients (Saettini et al, 2021). Immunological assessment (immunoglobulin levels, vaccine titers, and lymphocyte subsets with B cell phenotyping) in RSTS patients, who may require specific treatment if immune workup results impaired, is recommended.…”

“…We have recently described a large cohort of 97 RSTS patients with variable immunodeficiency (Saettini et al, 2020). Here we characterize two patients (the first of whom has been previously described; Saettini et al, 2018Saettini et al, , 2021 who, despite carrying the same EP300 variant, show distinctive RSTS features (including congenital heart abnormalities, short stature, feeding problems, and gastroesophageal reflux; Figure 1a) but distinct clinical manifestations and immunological features.…”