At birth, the child weighed 8 lb 4 oz after a 39-week gestation that was complicated by a single abnormal diabetes screen. The mother was 35 and the father 31 years at the time of pregnancy. The delivery and nursery stay were uneventful, and the child was breast-fed successfully. The child had mild jaundice and a normal hearing screen.
At age 3 months, the child could fix and follow, lift his head well, roll over from front to back, and respond appropriately to noises. He exhibited excellent growth and was well nourished; his length was in the 50th percentile, weight in the 15th percentile, and head circumference in the 50th percentile. Physical findings were normal except for the bilateral ear anomalies and neck sinuses.
The patient had 2 half-brothers through his mother. One had congenital sensorineural deafness that required the use of hearing aids; the other half-sibling had no hearing defects. A 2-year-old full-brother was healthy except for neonatal hyperbilirubinemia that necessitated phototherapy (bilirubin levels had reached 19 mg/dL). This brother had recently reached a plateau in speech progression; he also had a grade 2 systolic ejection murmur that was investigated by a cardiologist who judged it to be functional.
The patient’s mother was healthy. She had a cyst over her left ear that resolved during childhood and mild changes in her external ears. The maternal grandmother also had draining neck sinuses at birth, which necessitated multiple operations because of infections. The grandmother had congenital hearing loss and required hearing aids; she also had congenital right-sided Bell palsy. This grandmother’s 3 sisters and their 2 offspring were healthy, as was the father’s side of the family. Differently patterned shading in the pedigree (Figure 2) reflects the different findings described for the patient and his family members.
What additional studies should be considered For this patient? Also, what disorder(s) should be considered in this patient and his family?
(Answer and discussion begin on the next page.)