Deletion is a mutation in which part of the chromosome or DNA is missing or lost. This may be inherent or due to inappropriate chromosomal crossing over during meiosis. This suppression is responsible for the abnormalities in the patient. One of the known disorders seen due to the deletion is Wolf-Hirschhorn syndrome. Wolf-Hirschhorn syndrome (WHS), first described by Wolf et al[1] and Hirschhorn et al[2], results from hemizygous deletion of the short distal part. arm of chromosome 4. Due to the complex and unmarked expression of this disorder, WHS syndrome is presumed to be a contiguous gene syndrome with an indeterminate number of genes responsible for the phenotype, i.e. a multigenic etiology . [3][4]The size of the terminal deletion can vary from a subtle 1.4 MB to a classic 30 MB [5]. Previous genotype-phenotype correlation studies reveal that the main characteristic of WHS – the “Greek warrior's helmet face”, is due to hemizygosity of the WHSC1 gene located in the WHS critical region (WHSCR).[5] Various other genes are also located in the WHSCR and are responsible for most other phenotypic characteristics. Specifically, the Wolf-Hirschhorn syndrome critical region (WHSCR) is located in region 4p16.3. Approximately 25% of patients with a WHS deletion in this region are not detectable by cytogenetic karyotyping [6]. Therefore, FISH should be performed. The prevalence of this syndrome is estimated at 1 in 50,000 births [7] with a female/male ratio of 2:1 [8]. Case Report: A baby was born with a low birth weight of 1.8 kg to a 36-year-old father and a 32-year-old mother. The proposita is the 6th daughter of non-consanguineous parents. As shown in the pedigree table presented in Figure 2, the mother...... middle of paper ......infant with Wolf-Hirschhorn syndrome: a dilemma in determining the optimal timing of delivery . Clinical medicine: case reports.8. Society for the Study of Behavioral Phenotypes (SSBP) Fact Sheet: Wolf-Hirschhorn syndrome. Registered charity number 1013849.9. Altherr, MR, Bengtsson, U., Elder, FFB, Ledbetter, DH, Wasmuth, JJ, McDonald, ME, Gusella, JF, Greenberg, F. Molecular confirmation of Wolf-Hirschhorn syndrome with a subtle translocation of chromosome 4. Am . J. Hmm. Broom. 49: 1235-1242, 1991. [PubMed: 1746553]10. Althea T. Impact of chromosome 4p syndrome on communication and expressive language skills: a preliminary investigation. Language, speech and hearing services in schools. Vol 41 265-276 July 2010.11. Harold Chen. Specialties EMedicine> Pediatrics: Genetics and Metabolic Diseases> Genetics. Updated in June 16, 2009.