ESPE Abstracts

Background: Terminal deletions of chromosome 15q are associated with different degrees of pre- and post-natal growth failure, dysmorphic features, functional impairments and congenital anomalies. Although monosomies of 15q26 do not represent a classical contiguous gene syndrome, candidate genes for selected features have been identified. Short stature is referred to deletions of the IGF1-R gene, located on 15q26.3. We demonstrate evidence of phenotype comparable with 15q26 monosomy in a family with microdeletion of 15q26.3 not involving IGF1-R gene.

Case presentation: An 8 years old girl was referred for short stature and minor dysmorphic features. Past history showed congenital hearth defect, repaired at 1.75 years, and infantile spasms since 6 months. IQ was mild impaired on verbal scales. After birth, height presented a progressive decline, achieving −3 S.D., far from the target height (S.D. – 1.44). Bone age was mildly delayed. She presented minor dysmorphisms including mild down-slunting eyelid, micrognathia, overjet with prominent incisors, short philtrum, arched palate. GH and IGF1 productions were normal. Array-CGH showed a microdeletion of the 15q chromosome, on the sub-terminal region 15q26.3 (chr15: 100167695–102364500) of about 2.5 Mb not involving the IGF1-R gene. The same deletion was found in the father. Father’s final height was found on the lowest part of the normal range. His past history was characterised by mild learning difficulties. He also presented truncal obesity and nocturnal sleep apneas.

Conclusion: To the best of our knowledge, this is the first case of terminal 15q deletion with a phenotype similar to others reported, not involving the IGF1-R gene. Deletion’s size seems not to be a predictor of the breadth of the phenotypic spectrum and the wide clinical variability suggests that other genetic mechanisms may be involved and need to be investigated.