Prader-Willi Syndrome: Early Diagnosis, Neonatal Hypotonia, and Angelman Differentiation

The Prader-Willi syndrome (PWS) is a complex genetic disorder that affects multiple body systems. It is characterized by the lack of expression of genes in the 15q11.2-q13 region of the paternal chromosome. This syndrome presents a series of clinical manifestations that change with age, beginning with neonatal hypotonia and feeding difficulties, and evolving into hyperphagia, behavioral problems, and cognitive disabilities in later stages of life. The 15q11-q13 deletion is one of the main genetic causes of this syndrome, along with maternal uniparental disomy and imprinting defects.

Early diagnosis of Prader-Willi syndrome is crucial for implementing early interventions that can improve the quality of life for patients. The DNA methylation analysis is the only technique that allows for the diagnosis of PWS in all its molecular genetic classes and differentiates it from Angelman syndrome, which shares the same critical region on chromosome 15 but presents with a different clinical phenotype.

Angelman syndrome is characterized by a distinct phenotype that includes developmental delay, balance and coordination problems, and a characteristic behavior that includes frequent laughter. Differentiating between these two syndromes is essential, as management and treatment strategies vary significantly. Standard cytogenetic analysis and FISH are methods used to identify the chromosomal abnormalities responsible for these syndromes.

In the context of hyperphagia, a prominent symptom in PWS, it has been observed that while other neurogenetic disorders may present similar symptoms, the hyperphagic profile is more severe in PWS. This underscores the importance of accurate diagnosis to guide appropriate clinical management.

In conclusion, early diagnosis and precise differentiation between Prader-Willi syndrome and Angelman syndrome are fundamental for the effective management of these disorders. Understanding the genetic and clinical differences between these syndromes enables physicians to implement personalized treatment strategies that can significantly improve patient outcomes.

Referencias

• [1] Prader-Willi syndrome: a review of clinical, genetic, and endocrine findings.
• [2] The inv dup (15) or idic (15) syndrome (Tetrasomy 15q).
• [3] Specificity of Early Childhood Hyperphagia Profiles in Neurogenetic Conditions.

Created 13/1/2025