Potocki-Shaffer syndrome is a disorder that affects development of the bones, nerve cells in the brain, and other tissues. Most people with this condition have multiple noncancerous (benign) bone tumors called osteochondromas. In rare instances, these tumors become cancerous. People with Potocki-Shaffer syndrome also have enlarged openings in the two bones that make up much of the top and sides of the skull (enlarged parietal foramina). These abnormal openings form extra "soft spots" on the head, in addition to the two that newborns normally have. Unlike the usual newborn soft spots, the enlarged parietal foramina remain open throughout life.

The signs and symptoms of Potocki-Shaffer syndrome vary widely. In addition to multiple osteochondromas and enlarged parietal foramina, affected individuals often have intellectual disability and delayed development of speech, motor skills (such as sitting and walking), and social skills. Many people with this condition have distinctive facial features, which can include a wide, short skull (brachycephaly); a prominent forehead; a narrow bridge of the nose; a shortened distance between the nose and upper lip (a short philtrum); and a downturned mouth. Less commonly, Potocki-Shaffer syndrome causes vision problems, additional skeletal abnormalities, and defects in the heart, kidneys, and urinary tract.

Potocki-Shaffer syndrome is a rare condition, although its prevalence is unknown. Fewer than 100 cases have been reported in the scientific literature.

Potocki-Shaffer syndrome (also known as proximal 11p deletion syndrome) is caused by a deletion of genetic material from the short (p) arm of chromosome 11 at a position designated 11p11.2. The size of the deletion varies among affected individuals. Studies suggest that the full spectrum of features is caused by a deletion of at least 2.1 million DNA building blocks (base pairs), also written as 2.1 megabases (Mb). The loss of multiple genes within the deleted region causes the varied signs and symptoms of Potocki-Shaffer syndrome.

In particular, deletion of the EXT2, ALX4, and PHF21A genes are associated with several of the characteristic features of Potocki-Shaffer syndrome. Research shows that loss of the EXT2 gene is associated with the development of multiple osteochondromas in affected individuals. Deletion of another gene, ALX4, causes the enlarged parietal foramina found in people with this condition. In addition, loss of the PHF21A gene is the cause of intellectual disability and distinctive facial features in many people with the condition. The loss of additional genes in the deleted region likely contributes to the other features of Potocki-Shaffer syndrome.

Genetic Testing Information

• Genetic Testing Registry: Potocki-Shaffer syndrome

Genetic and Rare Diseases Information Center

• Potocki-Shaffer syndrome

Patient Support and Advocacy Resources

• National Organization for Rare Disorders (NORD)

Clinical Trials

• ClinicalTrials.gov

Catalog of Genes and Diseases from OMIM

• POTOCKI-SHAFFER SYNDROME

Scientific Articles on PubMed

• PubMed

• Hall CR, Wu Y, Shaffer LG, Hecht JT. Familial case of Potocki-Shaffer syndrome associated with microdeletion of EXT2 and ALX4. Clin Genet. 2001 Nov;60(5):356-9. doi: 10.1034/j.1399-0004.2001.600506.x. Citation on PubMed
• Kim HG, Kim HT, Leach NT, Lan F, Ullmann R, Silahtaroglu A, Kurth I, Nowka A, Seong IS, Shen Y, Talkowski ME, Ruderfer D, Lee JH, Glotzbach C, Ha K, Kjaergaard S, Levin AV, Romeike BF, Kleefstra T, Bartsch O, Elsea SH, Jabs EW, MacDonald ME, Harris DJ, Quade BJ, Ropers HH, Shaffer LG, Kutsche K, Layman LC, Tommerup N, Kalscheuer VM, Shi Y, Morton CC, Kim CH, Gusella JF. Translocations disrupting PHF21A in the Potocki-Shaffer-syndrome region are associated with intellectual disability and craniofacial anomalies. Am J Hum Genet. 2012 Jul 13;91(1):56-72. doi: 10.1016/j.ajhg.2012.05.005. Epub 2012 Jul 5. Citation on PubMed or Free article on PubMed Central
• Montgomery ND, Turcott CM, Tepperberg JH, McDonald MT, Aylsworth AS. A 137-kb deletion within the Potocki-Shaffer syndrome interval on chromosome 11p11.2 associated with developmental delay and hypotonia. Am J Med Genet A. 2013 Jan;161A(1):198-202. doi: 10.1002/ajmg.a.35671. Epub 2012 Dec 13. Citation on PubMed
• Romeike BF, Wuyts W. Proximal chromosome 11p contiguous gene deletion syndrome phenotype: case report and review of the literature. Clin Neuropathol. 2007 Jan-Feb;26(1):1-11. doi: 10.5414/npp26001. Citation on PubMed
• Swarr DT, Bloom D, Lewis RA, Elenberg E, Friedman EM, Glotzbach C, Wissman SD, Shaffer LG, Potocki L. Potocki-Shaffer syndrome: comprehensive clinical assessment, review of the literature, and proposals for medical management. Am J Med Genet A. 2010 Mar;152A(3):565-72. doi: 10.1002/ajmg.a.33245. Citation on PubMed
• Wakui K, Gregato G, Ballif BC, Glotzbach CD, Bailey KA, Kuo PL, Sue WC, Sheffield LJ, Irons M, Gomez EG, Hecht JT, Potocki L, Shaffer LG. Construction of a natural panel of 11p11.2 deletions and further delineation of the critical region involved in Potocki-Shaffer syndrome. Eur J Hum Genet. 2005 May;13(5):528-40. doi: 10.1038/sj.ejhg.5201366. Citation on PubMed
• Wuyts W, Waeber G, Meinecke P, Schuler H, Goecke TO, Van Hul W, Bartsch O. Proximal 11p deletion syndrome (P11pDS): additional evaluation of the clinical and molecular aspects. Eur J Hum Genet. 2004 May;12(5):400-6. doi: 10.1038/sj.ejhg.5201163. Citation on PubMed