Concurrent Noonan Syndrome and Sanjad-Sakati Syndrome in a Newborn: First Genetically Confirmed Dual Diagnosis
Year: 2026
Type: preprint
Study design: Case Report
Abstract: Purpose : To describe the first genetically confirmed coexistence of Noonan syndrome and Sanjad-Sakati syndrome in a newborn and to highlight the diagnostic challenges posed by overlapping and blended phenotypes. Methods : A case report of an infant with dual molecular diagnoses of Noonan syndrome and Sanjad-Sakati syndrome based on clinical, biochemical, radiological, and genomic findings. Results : A male infant born at 36 weeks’ gestation with severe intrauterine growth restriction, non-immune hydrops fetalis, and phenotypic features suggestive of Noonan syndrome. His clinical course was complicated by bilateral pleural effusions, congenital heart disease, severe gastroesophageal reflux with aspiration pneumonia, renal dysplasia with nephrocalcinosis, congenital hypothyroidism, hypoparathyroidism with hypocalcemic seizures, persistent thrombocytopenia, and recurrent multidrug-resistant sepsis. Whole-exome sequencing identified a heterozygous pathogenic RIT1 variant, confirming Noonan syndrome, and a homozygous pathogenic TBCE variant, confirming Sanjad-Sakati syndrome; heterozygous CYP21A2 and POLG carrier variants were also detected. The infant died at 142 days of life from refractory septic shock and multiorgan failure. Conclusions : This first genetically confirmed coexistence of Noonan syndrome and Sanjad-Sakati syndrome highlights the diagnostic challenges of blended phenotypes and emphasizes the value of early genomic testing, multidisciplinary care, and genetic counseling.
Source: Research Square
Institution: Farwaniya Hospital
Language: English
Topic: Genomics and Rare Diseases
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7204091659