Case 450 -- A newborn with trisomy 21 and elevated level of C5-hydroxy acylcarnitine
Contributed by Ahmed Bedeir MD and K Michael Gibson, PhD, FACMG
Published on line in January 2006
This is a newborn female with trisomy 21 who also had abnormal newborn screening test showing elevation of C5-hydroxy acylcarnitine. Urine organic acid analysis revealed elevation of 3-hydroxyisovaleric acid and 3-methylcrotonylglycine. Further testing included skin biopsy for fibroblast cultures and assay of 3-methylcrotonyl-CoA carboxylase activity that was significantly below the control range (6% of normal).
History : The mother mentioned that the baby has some constipation but no other problems.
PHYSICAL EXAMINATION (at 7 months):
- VITAL SIGNS: Respiratory rate 30, pulse 128
- HEAD CIRCUMFERENCE: 41 cm (3-10th %).
- LENGTH: 60 cm (5-25th %).
- WEIGHT: 6.6 kg (50-75th %).
- LENGTH FOR WEIGHT: 90th %
- GENERAL APPEARANCE: happy and in no acute distress.
- HEENT: She has trisomy 21 facies. Her fontanels appear closed at this time. She had a normal oropharynx with mucus membranes that were pink and moist.
- LUNGS: Clear to auscultation.
- CV: S1 and S2 without murmur, rub or gallop. Normal perfusion and pulses.
- ABDOMEN: No hepatosplenomegaly.
- SKIN: No evidence of birthmarks, rashes or bruises.
- Bilateral clinodactyly
- Small hands and feet and a short finger-to-palm ratio consistent with her trisomy 21.
- Full passive range of motion. No erythema, swelling or tenderness
- MENTAL STATUS: She is alert and very social. She has consonant-based babbling.
- CRANIAL NERVES: Cranial nerves II-XII grossly intact including pupillary, EOM, hearing, facial symmetry, gag, tongue movements and suck
- MOTOR: HYPOTONIA more significantly noted in her lower extremities than upper extremities at this time. She does appear to have normal mass, strength, praxis and fine motor activity.
- SENSORY: Normal response to light touch and vibration
- REFLEXES: +2 throughout, equivocal toes, no clonus.