What are the common signs seen in children with 3MC syndrome?
Children with 3MC syndrome may share certain physical characteristics. These can include a wide space between the eyes, droopy eyelids, a cleft lip or palate, and a small bump or "tail-like" structure at the lower back (called a caudal appendage). Some children may also have short stature, curved fingers, or differences in the shape of their arms or legs.
Health problems may also affect the kidneys, genitals, heart, or eyes. For example, boys may be born with undescended testicles or other differences in the urinary system. Some children may have hearing loss, which can be present from birth.
Although many children have normal intelligence, others may have mild developmental delays, particularly in walking or speech. Learning and behavior may also be affected in some cases.
How do doctors diagnose 3MC syndrome?
Doctors may begin to suspect 3MC syndrome when they notice certain features, especially if more than one part of the body is affected. However, the appearance alone is not enough to make a diagnosis. Because 3MC syndrome is very rare, and can look similar to other conditions, a genetic test is needed to confirm it.
A diagnosis is usually made through a blood test that looks for changes in genes related to 3MC syndrome — especially MASP1, COLEC11, or COLEC10. The condition is more often seen in children whose parents are related (such as cousins), but it can also occur in families without any known history.
A more detailed explanation of the condition is available in the Professionals – Clinical Characteristicssection.