Seckel syndrome

Seckel syndrome, or microcephalic primordial dwarfism (also known as bird-headed dwarfism, Harper's syndrome, Virchow–Seckel dwarfism and bird-headed dwarf of Seckel) is an extremely rare congenital nanosomic disorder. Inheritance is autosomal recessive. It is characterized by intrauterine growth retardation and postnatal dwarfism with a small head, narrow bird-like face with a beak-like nose, large eyes with down-slanting palpebral fissures, receding mandible and intellectual disability.

A mouse model has been developed. This mouse model is characterized by a severe deficiency of ATR protein. These mice suffer high levels of replicative stress and DNA damage. Adult Seckel mice display accelerated ageing. These findings are consistent with the DNA damage theory of aging.

Symptoms

Symptoms include:

• intellectual disability (more than half of the patients have an IQ below 50)
• microcephaly
• sometimes pancytopenia (low blood counts)
• cryptorchidism
• low birth weight
• dislocations of pelvis and elbow
• unusually large eyes
• low ears
• small chin

Genetics

It is supposed to be caused by defects of genes on chromosome 3 and 18. One form of Seckel syndrome can be caused by mutation in the gene encoding the ataxia telangiectasia and Rad3 related protein (Template:Gene) which maps to chromosome 3q22.1-q24. This gene is central in the cell's DNA damage response and repair mechanism.

Types include:

Type	OMIM	Gene	Locus
SCKL1	210600	ATR	3q22-q24
SCKL2	606744	?	18p11-q11
SCKL3	608664	?	14q
SCKL4	613676	CENPJ	13q12

History

The syndrome was named after American physician Helmut Paul George Seckel (1900–1960). The synonym Harper's syndrome was named after Rita G. Harper.

See also

• Koo-Koo the Bird Girl

External links

Classification	ICD-10: Q87.1 ICD-9-CM: 759.89 OMIM: 210600 DiseasesDB: 31625
External resources	Orphanet: 808

• Seckel's syndrome at Who Named It?