How to use… microarray comparative genomic hybridisation to investigate developmental disorders.

Area of Science:

• Genetics
• Genomics
• Developmental Biology

Background:

• Conventional karyotyping has limitations in detecting sub-microscopic chromosomal abnormalities.
• Early developmental impairments often involve complex genetic factors.

Purpose of the Study:

• To evaluate the utility of array-comparative genomic hybridisation (array-CGH) as a first-line genetic test.
• To highlight the importance of interpreting array-CGH results in the context of clinical findings.

Main Methods:

• Array-comparative genomic hybridisation (array-CGH) for high-resolution chromosomal analysis.
• Comparison of diagnostic yield with conventional karyotyping.

Main Results:

• Array-CGH detects microdeletions and microduplications missed by conventional karyotyping.
• Array-CGH trebles the frequency of diagnosis compared to conventional karyotyping.
• Genomic findings often require careful interpretation due to technical complexity and uncertain clinical significance.

Conclusions:

• Array-CGH is a powerful tool for investigating developmental impairments, especially when associated with dysmorphism, growth abnormalities, congenital anomalies, epilepsy, or autism.
• Multidisciplinary collaboration among paediatricians, clinical geneticists, and scientists is essential for accurate interpretation and clinical application of array-CGH results.