Additive congenital anomaly patterns.

Area of Science:

• Medical Genetics
• Pediatrics
• Public Health

Background:

• Multiple congenital abnormality (MCA) patterns often present diagnostic challenges.
• Understanding familial recurrence of congenital abnormalities (CAs) is crucial for genetic counseling and risk assessment.

Purpose of the Study:

• To investigate the familial occurrence of congenital abnormalities in index patients with unidentified MCA patterns.
• To explore potential causal connections between parental and offspring anomalies in these families.

Main Methods:

• A family study was conducted using population-based data from the Hungarian Congenital Malformation Registry (HCMR).
• 1,038 index patients with unidentified MCA patterns were analyzed.
• Prevalence of CAs in parents and similarity of MCA patterns between affected parents and children were assessed.

Main Results:

• Congenital abnormalities were detected in 5.1% of fathers and 4.2% of mothers.
• In over 50% of affected parent-child pairs, a component CA of the child was present in the parent, suggesting a potential causal link.
• The concept of an "additive CA pattern" was introduced to describe combinations of CAs from different parental origins.

Conclusions:

• A significant proportion of unidentified MCA patterns may arise from additive CA patterns inherited from parents.
• These findings highlight the importance of family history and parental examination in evaluating congenital abnormalities.
• Further research into the genetic and environmental factors contributing to additive CA patterns is warranted.