Document Type : case report


1 Student Research Committee, Sabzevar University of Medical Sciences, Sabzevar, Iran

2 General Paediatrics, Evelina London Children’s Hospital, Guy’s and St. Thomas’ National Health Service Foundation Trust, London, United Kingdom

3 Department of Pediatric Endocrinology and Metabolism, Faculty of Medicine, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran.


Wiedemann-Steiner syndrome (WDSTS) is an exceptionally rare genetic syndrome characterized by postnatal growth retardation, facial dysmorphism, hairy elbow, and short stature. It is known that the occurrence of WDSTS is due to mutations in KMT2A gene. It is noteworthy that not a great number of WDSTS have been identified yet; thereby, new phenotypes and features continue to be added. In this report, we describe a 5-year-old male patient presented with developmental delay, hypothyroidism, facial dysmorphism, and behavioral signs such as autistic spectrum features. By Whole Exome Sequencing (WES), a new mutation in KMT2A was found and WDSTS was diagnosed genetically. According to a genetic test, a variant in exon 27 of the KMT2A gene c.6647delT (p.Pro2215fs) was found. This mutation was not reported previously, also this case was the first WDSTS diagnosed in Iran. This syndrome is a rare genetic disorder representing a broad range of phenotypes. The mentioned low frequency emphasizes the importance of a phenotype-genotype correlation to be established. The phenotype comparison between our case and previously reported patient did not reveal any difference related to age or sex in patients with WDSTS


  1. Jones WD, Dafou D, McEntagart M, Woollard WJ, Elmslie FV, Holder-Espinasse M, Irving M, Saggar AK, Smithson S, Trembath RC, Deshpande C, Simpson MA. De novo mutations in MLL cause Wiedemann-Steiner syndrome. Am J Hum Genet. 2012; 91(2):358-64.
  2. Min Ko J, Cho JS, Yoo Y, Seo J, Choi M, Chae JH, Lee HR, Cho TJ. Wiedemann-Steiner Syndrome With 2 Novel KMT2A Mutations: Variable Severity in Psychomotor Development and Musculoskeletal Manifestation. Journal of child neurology. 2017; 32(2):237-42.
  3. Hirst L, Evans R. Wiedemann-Steiner syndrome: A case report. Clin Case Rep. 2021; 9(3):1158-62.
  4. Feldman HR, Dlouhy SR, Lah MD, Payne KK, Weaver DD. The progression of Wiedemann–Steiner syndrome in adulthood and two novel variants in the KMT2A gene. American Journal of Medical Genetics Part A. 2019; 179(2):300-5.
  5. Wiedemann H-R, Kunze J, Grosse F, Dibbern H. A syndrome of abnormal facies, short stature, and psychomotor retardation. Atlas of clinical syndromes: A visual aid to diagnosis for clinicians and practicing physicians. 1989:198-9.
  6. Steiner C, Marques A. Growth deficiency, mental retardation and unusual facies. Clinical dysmorphology. 2000; 9(2):155-6.
  7. Biesecker LG, Green RC. Diagnostic clinical genome and exome sequencing. New England Journal of Medicine. 2014; 370(25):2418-25.
  8. Ali M, Hom RA, Blakeslee W, Ikenouye L, Kutateladze TG. Diverse functions of PHD fingers of the MLL/KMT2 subfamily. Biochimica Et Biophysica Acta (BBA)-Molecular Cell Research. 2014; 1843(2):366-71.
  9. Ansari KI, Mishra BP, Mandal SS. MLL histone methylases in gene expression, hormone signaling and cell cycle. Front Biosci. 2009; 14:3483-95.
  10. Miyake N, Tsurusaki Y, Koshimizu E, Okamoto N, Kosho T, Brown NJ, et al. Delineation of clinical features in Wiedemann–Steiner syndrome caused by KMT2A mutations. Clinical genetics. 2016; 89(1):115-9.
  11. Ramirez-Montaño D, Pachajoa H. Wiedemann-Steiner syndrome with a novel pathogenic variant in KMT2A: a case report. Colombia médica. 2019; 50(1):40-5.
  12. Jinxiu L, Shuimei L, Ming X, Jonathan LC, Xiangju L, Wenyuan D. Wiedemann-steiner syndrome with a de novo mutation in KMT2A: A case report. Medicine. 2020; 99(16).
  13. Sun Y, Hu G, Liu H, Zhang X, Huang Z, Yan H, Wang L, Fan Y, Gu X, Yu Y. Further delineation of the phenotype of truncating KMT2A mutations: The extended Wiedemann–Steiner syndrome. American Journal of Medical Genetics Part A. 2017; 173(2):510-4.
  14. Aggarwal A, Rodriguez-Buritica DF, Northrup H. Wiedemann-Steiner syndrome: Novel pathogenic variant and review of literature. European journal of medical genetics. 2017; 60(6):285-8.
  15. Vissers LE, Gilissen C, Veltman JA. Genetic studies in intellectual disability and related disorders. Nature Reviews Genetics. 2016; 17(1):9-18.