Beyond 'speech delay': Expanding the phenotype of BRPF1-related disorder.

Pathogenic variants in BRPF1 cause intellectual disability, ptosis and facial dysmorphism. Speech and language deficits have been identified as a manifestation of BRPF1-related disorder but have not been systematically characterized. We provide a comprehensive delineation of speech and language abilities in BRPF1-related disorder and expand the phenotype. Speech and language, and health and medical history were assessed in 15 participants (male = 10, median age = 7 years 4 months) with 14 BRPF1 variants. Language disorders were common (11/12), and most had mild to moderate deficits across receptive, expressive, written, and social-pragmatic domains. Speech disorders were frequent (7/9), including phonological delay (6/9) and disorder (3/9), and childhood apraxia of speech (3/9). All those tested for cognitive abilities had a FSIQ ≥70 (4/4). Participants had vision impairment (13/15), fine (8/15) and gross motor delay (10/15) which often resolved in later childhood, infant feeding impairment (8/15), and infant hypotonia (9/15). We have implicated BRPF1-related disorder as causative for speech and language disorder, including childhood apraxia of speech. Adaptive behavior and cognition were strengths when compared to other monogenic neurodevelopmental chromatin-related disorders. The universal involvement of speech and language impairment is noteable, relative to the high degree of phenotypic variability in BRPF1-related disorder.

Anemia and thrombocytopenia due to a novel BRPF1 variant in a family from Çanakkale with intellectual disability and dysmorphic facies: Case report and review of the literature.

Intellectual developmental disorder with dysmorphic facies and ptosis (IDDDFP) (MIM#617333) is an autosomal dominant disorder characterized by delayed psychomotor development, intellectual disability (ID), and dysmorphic facial features due to pathogenic variations in the Bromodomain- and PHD Finger-Containing Protein (BRPF1) (MIM#602410) gene. Herein, we report the first Turkish patients with IDDDFP. Additionally, the patients had hematopoietic disorders such as anemia and thrombocytopenia, which have not been previously described in IDDDFP patients. Genetic testing using Whole Exome Sequencing (WES) revealed a novel heterozygous c.1433G > A; p.W478* (NM_004634.3) pathogenic variant on exon 3 of the BRPF1 gene. The patients demonstrated classical features of IDDDFP such as intellectual disability, developmental delay, ptosis, micro and retrognathia, and dysmorphic facial features, in addition to the anemia and thrombocytopenia. Apart from the variant in BRPF1, no additional genomic changes were detected by WES and chromosomal microarray analysis (CMA). Hopefully, our novel report on the hematopoietic anomalies of our patients due to BRPF1 will expand upon the clinical spectrum of IDDDFP, encourage further studies about BRPF1-hematopoietic system relations, and affect the diagnostic and therapeutic schemes of hematopoietic system disorders.