New dysmorphic features in Rubinstein-Taybi syndrome.

Area of Science:

• Medical Genetics
• Pediatric Cardiology
• Developmental Pediatrics

Background:

• Rubinstein-Taybi syndrome (RTS) is a rare genetic disorder characterized by intellectual disability, distinctive facial features, and broad thumbs and toes.
• RTS is typically associated with mutations in the CREBBP or EP300 genes, affecting chromatin remodeling.
• While common features are documented, significant inter- and intra-familial variability exists, necessitating detailed case reporting.

Observation:

• A 3-month-old infant presented with classic Rubinstein-Taybi syndrome features including broad thumbs/big toes, bilateral finger syndactyly, beaked nose, and broad nasal columella.
• The patient exhibited significant congenital anomalies: hypoplastic right kidney, persistent pulmonary hypertension, and mitral valve regurgitation.
• Additional findings included patent ductus arteriosus and delayed motor and mental development, with the infant functioning at a 1-month-old level.

Findings:

• This case expands the known phenotype of Rubinstein-Taybi syndrome by documenting a rare combination of renal hypoplasia and persistent pulmonary hypertension.
• The presence of mitral valve regurgitation and patent ductus arteriosus further underscores the cardiovascular involvement in this specific RTS presentation.
• The severe developmental delay highlights the impact of RTS on neurodevelopmental trajectories.

Implications:

• This case contributes to a better understanding of the phenotypic variability within Rubinstein-Taybi syndrome, particularly concerning congenital anomalies.
• Recognizing this constellation of symptoms can aid in earlier diagnosis and more comprehensive management strategies for affected infants.
• Further research into genotype-phenotype correlations may elucidate the mechanisms underlying these specific anomalies in RTS.