SNP Shot: Genomic Insights

Menkes syndrome is a condition that disrupts the body's ability to process copper, leading to low copper levels. This results in distinctive symptoms like sparse, brittle, and twisted hair; poor weight gain and stunted growth (failure to thrive); and progressive damage to the nervous system. Other signs can include weak muscles (hypotonia), drooping facial features, seizures, delayed development, and intellectual disability. Symptoms usually appear in infancy, and unfortunately, most children with Menkes syndrome do not survive beyond the age of 3. However, early copper treatment may improve outcomes for some patients. In rare instances, the onset of symptoms occurs later in childhood.

Occipital horn syndrome, also known as X-linked cutis laxa, is a milder variant of Menkes syndrome that appears between early and middle childhood. It is defined by calcium deposits shaped like wedges in the occipital bone (located at the base of the skull), along with coarse hair, and loose, flexible skin and joints.

Inheritance:

Menkes syndrome follows an X-linked recessive inheritance pattern. The responsible gene resides on the X chromosome, one of the two sex chromosomes. Males, possessing only one X chromosome, develop the condition if they inherit one altered copy of the gene. Females, with two X chromosomes, would need mutations in both copies to be affected. Consequently, X-linked recessive disorders are far more prevalent in males than females. A key feature of X-linked inheritance is that affected fathers cannot transmit X-linked traits to their sons. Approximately one-third of Menkes syndrome cases arise from new mutations in the ATP7A gene. Individuals with these new mutations have no family history of the condition.