Paediatric Teratoid/Rhabdoid Tumours: Germline Deletions of Chromosome 22q11.2

The 22q11.2 Microdeletion in Pediatric Patients with Cleft Lip, Palate, or Both and Congenital Heart Disease: A Systematic Review

“…The phenotypes most commonly associated with distal deletions (LCR-D-LCR-H) are premature birth, growth and developmental delay, facial abnormalities, skeletal defects, and increased risk of developing tumors. 32,42,43 The CL/P populations included in this review were from different parts of the world (Israel, Germany, Boston, United Kingdom, and South Asia) and large variations in the frequencies of the 22q11.2 microdeletions were observed (0-13%). This may be due to the fact that among the characteristics of patients with 22q11.2DS, included ethnicity and geographical origin.…”

“…The most common phenotypes are palatal abnormalities, facial dysmorphism, congenital craniofacial abnormalities, hypocalcemia, immunodeficiency, urogenital defects, risk of developing malignant rhabdoid tumors, developmental delay, behavioral, psychiatric disorders, decreased cognitive and motor skills, and intellectual disability. [23][24][25][26][27][28][29][30][31][32] ►Table 1 summarizes the most common phenotypes in patients with the 22q11.2 microdeletion.…”

“…This region harbors eight blocks of low copy repeats (LCRs) that make it susceptible to conformational changes. 13,18,32,41 Approximately 90% of the 22q11.2 microdeletions are de novo mutations that occur during fetal development, and 10% are inherited from parents with less marked phenotypes. The hemizygous 22q11.2 deletion is transmitted as a contiguous gene deletion syndrome; therefore, the children of the patients with 22q11.2 microdeletion syndrome have a 50% chance of being impacted.…”

“…Distal deletions range from LCR-D to LCR-H and are mainly associated with premature birth, growth, delayed development, facial abnormalities, skeletal defects, increased risk of developing rhabdoid tumors, and increased cardiac defects related to the truncus arteriosus. 32,42,43 It is worth noting that the rhabdoid tumors have been observed in individuals with distal deletions including the SMARCB1 gene. 44,45 It has been reported that the q11.2 region of chromosome 22 contains more than 90 overlapping genes that are associated with different phenotypes that involve CL/P and CHD.…”