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Diagnosis of Angelman syndrome in infants
J S Fryburg1, W R Breg, V Lindgren
1Department of Human Genetics, Yale University School of Medicine, New Haven, CT 06510.
Insights
Diagnosing Angelman syndrome (AS) in infants is challenging due to delayed symptom onset. Early identification is possible through recognizing specific features like hypopigmentation and developmental delays in young children with AS.
Area of Science:
- Genetics
- Pediatrics
- Developmental Biology
Background:
- Angelman syndrome (AS) diagnosis is typically delayed due to characteristic manifestations appearing after age two.
- Infant diagnosis of AS is infrequent, hindering early intervention and management.
Observation:
- Four AS patients under two years old were evaluated, including one with oculocutaneous albinism.
- All patients presented with severe global developmental delay, postnatal microcephaly, seizures, hypotonia, hyperreflexia, and hyperkinesis.
- Hypopigmentation and various eye abnormalities, including choroidal pigment hypoplasia, were noted in all patients.
Findings:
- All four patients had deletions in the q11.2-q13 region of chromosome 15, with the deleted chromosome being maternally derived in three cases.
- The study highlights early-onset clinical features of AS in infants, including severe developmental delay, microcephaly, seizures, hypotonia, and hypopigmentation.
- A unique case of co-occurring albinism and AS is presented, suggesting a potential association.
Implications:
- AS may be more prevalent in infants than previously recognized.
- Early identification of AS in infants is crucial for timely intervention and improved outcomes.
- Recognizing subtle signs like hypopigmentation and specific developmental patterns can aid in earlier AS diagnosis.
Abstract:
The diagnosis of Angelman syndrome (AS) has seldom been made in infants because the previously described characteristic manifestations usually are not apparent until after age 2 years. We describe 4 AS patients, one of whom has oculocutaneous albinism, who were less than 2 years old when first evaluated. All 4 have deletions of the region q11.2-q13 of chromosome 15. In the 3 cases in which parents were available for study the deleted chromosome 15 was maternally derived, as determined by cytological markers. All of the patients presented with severe to profound global developmental delay and postnatal-onset microcephaly; they had seizures, hypotonia, hyperreflexia, and hyperkinesis. All were hypopigmented as compared to their relatives. Each had eye abnormalities; all had choroidal pigment hypoplasia. None were initially described as having an abnormal appearance. We believe that AS is far more common than previously thought and present these 4 children to emphasize the manifestations that may be helpful in making the diagnosis in the young patient. We also emphasize the hypopigmentation that patients with AS frequently have, including what we think is the first reported case of albinism and AS.