A 6-month-old child was at the 50th percentile at birth for length, weight, and head circumference. His growth curve from his last visit 1 week ago is shown. On his developmental assessment, you noted that he rolled from stomach to back occasionally but not very well from back to stomach. He could bear weight on his legs but would not sit without assistance. Today, the family calls you urgently at 7:00 AM noting that their child seems unable to move the right side of his body. Which of the following conditions might explain this child's condition?
The growth curve shown demonstrates poor growth over the 6 months of this child's life. Homocystinuria is an autosomal recessive metabolic disease caused by deficiencies of cystathionine b-synthase, methylenetetrahydrofolate reductase, or the coenzyme for N5-methyltetrahydrofolate methyltransferase. Manifestations include poor growth, arachnodactyly, osteoporosis, dislocated lenses, and mental retardation. In addition, thromboembolic phenomena may be seen in the pulmonary and systemic arteries and particularly in the cerebral vasculature; vascular occlusive disease is, in turn, one of the many causes of acute infantile hemiplegia. None of the other disorders listed in the question is associated with acute hemiplegia. Phenylketonuria causes retardation and, on occasion, seizures; maple syrup urine disease, an abnormality of the metabolism of leucine, leads to seizures and rapid deterioration of the CNS in newborn infants; and histidinemia and cystathioninuria are most likely a benign aminoaciduria with no effect on the CNS. Many states now include these diseases in their newborn screening programs.
Phenylketonuria
Homocystinuria
Cystathioninuria
Maple syrup urine disease
Musculo Skeletal Disorders