PMM2 and obsessive-compulsive disorder: Our case involves an isolated unilateral MCDK in a fetus born to a mother with generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), and gastroesophageal reflux disease (GERD), with the father having chronic occupational lead exposure and a congenital disorder of glycosylation type 1A (PMM2-CDG).