Seckel syndrome

Seckel syndrome is an extremely rare inherited disorder marked by severe growth restriction beginning before birth and a distinctive small head with facial features that have been likened to a bird's head, including a prominent, beaked nose and large, downward-slanting eyes. It is inherited in an autosomal recessive pattern and can result from mutations in any of several genes located across different chromosomes, with at least eleven genetically distinct types now recognized; the best-characterized form involves the ATR gene, which normally helps cells detect and respond to damaged DNA during replication. Affected individuals are born small and remain severely short throughout life, with a small head, intellectual disability that in many cases brings an IQ below 50, and skeletal abnormalities; some also develop reduced blood cell counts or, in males, undescended testicles. Diagnosis is guided by a set of clinical criteria covering prenatal-onset dwarfism with continued growth delay after birth, the characteristic small head and facial appearance, intellectual disability, and specific structural brain abnormalities seen on imaging, with genetic testing available to confirm the diagnosis in known gene types. There is no cure for Seckel syndrome; management is entirely supportive, addressing growth, developmental, orthopedic and other complications as they arise over a person's lifetime.