[2] It is characterized by intrauterine growth restriction and postnatal dwarfism with a small head, narrow bird-like face with a beak-like nose, large eyes with down-slanting palpebral fissures,[3] receding mandible and intellectual disability.

[4] This mouse model is characterized by a severe deficiency of ATR protein.

One form of Seckel syndrome can be caused by mutation in the gene encoding the ataxia telangiectasia and Rad3-related protein (ATR) which maps to chromosome 3q22.1–q24.

This gene is central in the cell's DNA damage response and repair mechanism.

[9][10] The syndrome was named after German–American physician Helmut Paul George Seckel[11] (1900–1960).