Growth patterns of patients with 1p36 deletion syndrome.

1p36 deletion syndrome is one of the most common subtelomeric deletion syndromes. Obesity is frequently observed in patients with this syndrome. Thus, it is important to evaluate the growth status of an individual patient. For this purpose, we accumulated recorded growth data from 44 patients with this syndrome and investigated the growth patterns of patients. Most of the patients showed weight parameters within normal limits, whereas a few of these patients showed intrauterine growth delay and microcephaly. The length of the patients after birth was under the 50th centile in most patients. Many patients showed poor weight gain after birth, and only two female patients were overweight. These findings indicate two different phenotypes of the 1p36 deletion syndrome. The overweight patients with 1p36 deletion started excessive weight gain after two years of life. This characteristic of the patients with 1p36 deletion syndrome is similar to Prader-Willi syndrome.