A recognizable pattern of the midface of retinoblastoma patients with interstitial deletion of 13q.

In our study, we found a recognizable pattern of the midface in three retinoblastoma patients with interstitial deletion of chromosome 13 in lymphocytes. Further photographs of patients reported by other authors confirmed our conclusion that the midface in children with interstitial deletion of 13q from q12 to q22, always involving q14, is characterized by prominent eyebrows, broad nasal bridge, bulbous tip of the nose, a large mouth with a thin upper lip, and a long philtrum. This midface pattern could not be recognized in patients with normal karyotypes, suggesting that the critical segment for the midface phenotype as well as for retinoblastoma may exist in band 13q14.