Jacobsen Syndrome is associated with a partial deletion of 11q. It is an MCA/MR contiguous gene syndrome (multiple congenital anomalies, mental retardation).
Most cases arise from de novo pure terminal deletion of 11q. Breakpoints are usually within or distal to subband 11q23.3 and extend to the telomere.
Clinical features:
(1) growth retardation at birth
(2) short stature
(3) psychomotor retardation
Facial dysmorphism:
(1) skull deformities with high, prominent forehead
(2) hypertelorism
(3) ptosis
(4) eyelid coloboma
(5) downslanting palpebral fissures
(6) epicanthal folds
(7) broad nasal bridge
(8) short nose
(9) prominent columella
(10) long philtrum
(11) thin upper lip
(12) v-shaped mouth
(13) retrognathia
(14) small ears
(15) low set posteriorly rotated ears
(16) short and/or webbed neck
Visceral malformations
(1) heart
(2) kidney
(3) gastrointestinal tract, which can result in feeding difficulties
(4) genitalia
(5) CNS
(6) bone
(7) deformities of hands and feet
Additional problems:
(1) thrombocytopenia including the Paris Trousseau syndrome, which may be associated with bleeding
(2) pancytopenia
(3) vision problems
(4) hearing problems
(5) recurrent otitis and sinusitis
(6) endocrine disorders
(7) difficult airway
