SNP Shot: Genomic Insights

Autosomal recessive primary microcephaly (MCPH), also known as "microcephaly primary hereditary," is characterized by newborns having an abnormally small head and brain. The term "microcephaly" originates from Greek, meaning "small head."

A key feature of MCPH is a significantly reduced head circumference in infants compared to their peers of the same sex and age. Head circumference is measured around the widest part of the head, just above the eyebrows and ears and around the back. In MCPH, the brain volume is also smaller than expected, but the brain's overall structure is typically normal. While the head and brain continue to develop, they remain considerably smaller than average throughout childhood and adolescence.

MCPH results in intellectual disability, typically ranging from mild to moderate, which does not worsen over time. Individuals with MCPH commonly experience delays in speech and language development. There may also be slight delays in motor skills development, like sitting, standing, and walking.

Individuals with MCPH often exhibit few or no additional characteristics. Some may have a narrow, sloping forehead; experience mild seizures; have difficulty with attention or behavior; or be shorter than other family members. Generally, MCPH does not impact other major organ systems or cause significant health issues.

Inheritance:

MCPH follows an autosomal recessive inheritance pattern. This means that both copies of the responsible gene in each cell must have a mutation for the condition to manifest. Parents of a child with MCPH each carry one mutated copy of the gene but usually do not exhibit any signs or symptoms themselves.