Inheritance: autosomal recessive
Genetic locus: COH1 on the long arm of chromosome 8
Criteria for diagnosis - at least 2 of the following:
(1) facial gestalt
(1a) thick hair
(1b) thick eyebrows and eyelashes
(1c) wave-shaped, downward slanting palpebral fissues (lateral canthus lower than medial canthus)
(1d) prominent, beaked nose
(1e) short, upturned philtrum (medial groove in upper lip)
(1f) grimacing expression when smiling
(2) pigmentary retinopathy (a retinal dystrophy)
(3) absolute neutropenia
where:
• The cutoff for the neutrophil count was < 2 * 10^(-9) per µL which is an impossible value.
• A common cutoff for neutropenia is < 2,000 per µL; significant neutropenia is < 500 per µL.
Additional findings:
(1) mental retardation
(2) microcephaly
(3) open-mouthed expression
(4) slim, tapering extremities
(5) relative truncal obesity in mid-childhood
(6) hypotonia
(7) joint laxity
(8) myopia
