Jacobsen syndrome Q93.5

Petrea Jacobsen 1973

Syndrome with multiple congenital anomalies immunodeficiency, and mental retardation (so-called MCA/MR syndrome).

More than 200 cases have been described to date. The prevalence at birth is estimated at 1:100,000, with a sex ratio m:w of 2:1.

Contiguous-gene syndrome with heterozygous loss of many genes due to partial deletion of the long arm of a chromosome 11. The size of the deletion ranges from approximately 7 to 20 Mb. The proximal breakpoint is within or telomeric to 11q23.3, and the deletion usually extends to the telomere. In 85% of cases, the deletion is newly originated; in 15%, it results from the unbalanced segregation of a familial balanced translocation or other chromosomal rearrangements. In a minority of cases, the breakpoint is in the fragile site FRA11B.

Malformations of the heart, kidney, gastrointestinal tract, genitalia, central nervous system, immune system and skeleton are common.

Specifically: Pre- and postnatally delayed growth, autism, immunodeficiency (antibody deficiency), craniofacial dysmorphia (cranial deformities, ptosis, coloboma, antimongoloid eyelid axes, epicanthus, broad nasal root, short nose, V-shaped mouth, and small, low-set, posteriorly rotated ears).

Furthermore: Abnormal platelet function, thrombocytopenia or pancytopenia usually exist at birth (Paris-Trousseau bleeding disorder).

Less common are abnormalities of the eyes, hearing and endocrine system.

Clinical picture (intellectual deficit, craniofacial dysmorphia, thromocytopenia); cytogenetic analysis .

Turner and Noonan syndrome, acquired thrombocytopenia in sepsis.

Multidisciplinary care (pediatrics, pediatric cardiology, neurology, ophthalmology). Tube feeding may be indicated in neonates with Jacobsen's syndrome.

About 20% of children die in the first two years of life, from cardiac problems; also from hemorrhage.

Nigolian H et al (2022) reported a patient with recurrent bacterial and persistent viral infections of the respiratory system and other classic features of the syndrome. Low IgM, IgG4; B cells. T helper and naive T cells also decreased.

1. Blazina Š et al. (2016) 11q terminal deletion and combined immunodeficiency (Jacobsen syndrome): Case report and literature review on immunodeficiency in Jacobsen syndrome. Am J Med Genet A 170:3237-3240.
2. Favier R et al (2015) Jacobsen syndrome: Advances in our knowledge of phenotype and genotype. Am J Med Genet C Semin Med Genet 169:239-250.
3. Nigolian H et al (2022) Immunodeficiency and lymphoma in Jacobsen syndrome. J Investig Allergol Clin Immunol doi: 10.18176/jiaci.0777.