The Diagnostic and Therapeutic Challenges of Schaaf-Yang Syndrome: A Brazilian Case Report.

This study reports on a 4-year-old Brazilian girl with Schaaf-Yang syndrome, an extremely rare condition that affects brain development. She had low muscle tone, delayed development, and facial differences. Genetic testing at age 2 confirmed the diagnosis. She also has autism. With a team approach including doctors, speech therapy, and psychology support, she showed significant improvements in movement, talking, memory, and learning.

This case report describes the first documented Brazilian case of Schaaf-Yang syndrome, an ultra-rare neurodevelopmental disorder affecting less than 1 in 50,000 people. A 4-year-old girl initially diagnosed with Prader-Willi syndrome was found to have a pathogenic MAGEL2 gene variant through genetic sequencing at age 2. She presented with hypotonia, developmental delays, craniofacial dysmorphism, growth hormone deficiency, and autism spectrum disorder. Multidisciplinary interventions including medical care, speech therapy, and psychological support resulted in notable improvements in motor function, language, memory, and learning abilities.

The case highlights the importance of genetic testing for accurate diagnosis and demonstrates the potential benefits of early, comprehensive intervention approaches.

Emphasizes need for genetic testing in children with Prader-Willi-like features and developmental delays. Supports early multidisciplinary intervention approaches. Highlights importance of considering Schaaf-Yang syndrome in differential diagnosis of neurodevelopmental disorders with hypotonia and autism features.

Single case report limits generalizability. No control group or standardized outcome measures reported. Specific intervention details and duration not clearly described. Long-term outcomes unknown.

Schaaf-Yang syndrome is an ultra-rare neurodevelopmental disorder caused by pathogenic variants in thegene, also implicated in Prader-Willi syndrome. With less than 1 case per 50 000 people, Schaaf-Yang syndrome remains underreported globally, and no previous cases have been documented in Brazil.This study presents a 4-year-old Brazilian girl clinically diagnosed with Prader-Willi syndrome, characterized by hypotonia, delayed neuropsychomotor development, and craniofacial dysmorphism. Initial assessments identified growth hormone deficiency and developmental delays, followed by genetic sequencing at 2 years of age, confirming a pathogenicvariant [NM_019066.5:c2821dup: p (Arg941Profs*10)]. The child was also diagnosed with autism spectrum disorder.

Multidisciplinary interventions, including medical care, speech therapy, and psychological support, led to remarkable improvements in motor function, language, memory, and learning.This is the first documented Brazilian case of Schaaf-Yang syndrome, emphasizing the critical role of early diagnosis and personalized interventions in reducing the impact of the syndrome.