Children with TBS and ZLS often come to medical attention because of delays in their development. Developmental delay tends to be more extreme in TBS compared to ZLS. Early clues to the diagnosis include small or absent nails of the thumbs or great toes. Other finger and toe nails may be small as well. Epilepsy can be seen in both conditions, but it is more common in TBS. Overgrowth of the gums is seen in both conditions, but this may not be apparent until later in life.
Children with TBS have a distinctive facial appearance, often referred to as ‘myopathic’. This just means the facial muscles appear droopy. The facial features in ZLS are different – there children often appear to have coarsened facial features. In addition, children with ZLS may have overgrowth of body hair (‘hirsutism’) and overgrowth of abdominal organs such as the liver and spleen.
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