Anthony and Brian(not their real names) are monozygotic(MZ) twins who were born by normal spontaneous vaginal delivery at full term following an unremarkable pregnancy. Labor lasted 3 hours, with Brian born by breech delivery 8 minutes after Anthony, who was born head first. Both twins were healthy at birth, Brian weighing 3000 g and Anthony 3254 g. Their neurodevelopmental milestones were normal and neither had learning disabilities or problems with hyperactivity, anxiety, phobias, or memory. From about 2 years of age, Brian was felt to be easily distracted and his gross motor skills also appeared to be less refined. Brian developed motor tics at age 6 years with eye blinking as the presenting symptom, and vocal tics began with sniffing at age 9 years. Anthony developed motor tics at age 7 years with eye blinking as the presenting symptom. He has never manifested vocal tics. The.
|Number of pages
|JAMA: The Journal of the American Medical Association
|Published - Feb 8 1995
ASJC Scopus subject areas
- General Medicine