Prominent and elongated coccyx, a new manifestation of KBG syndrome associated with novel mutation in ANKRD11

M.L. De Bernardi, I. Ivanovski, S.G. Caraffi, I. Maini, M.E. Street, A. Bayat, M. Zollino, F.R. Lepri, M. Gnazzo, E. Errichiello, A. Superti-Furga, L. Garavelli

Research output: Contribution to journalArticlepeer-review


KBG syndrome is characterized by short stature, distinctive facial features, and developmental/cognitive delay and is caused by mutations in ANKRD11, one of the ankyrin repeat-containing cofactors. After the advent of whole exome sequencing, the number of clinical reports with KBG diagnosis has increased, leading to a revision of the phenotypic spectrum associated with this syndrome. Here, we report a female child showing clinical features of the KBG syndrome in addition to a caudal appendage at the coccyx with prominent skin fold and a peculiar calcaneus malformation. Exons and exon–intron junctions targeted resequencing of SH3PXD2B and MASP1 genes, known to be associated with prominent coccyx, gave negative outcome, whereas sequencing of ANKRD11 whose mutations matched the KBG phenotype of the proband showed a de novo heterozygous frameshift variant c.4528_4529delCC in exon 9 of ANKRD11. This report contributes to expand the knowledge of the clinical features of KBG syndrome and highlights the need to search for vertebral anomalies and suspect this condition in the presence of a prominent, elongated coccyx. © 2018 Wiley Periodicals, Inc.
Original languageEnglish
Pages (from-to)1991-1995
Number of pages5
JournalAmerican Journal of Medical Genetics, Part A
Issue number9
Publication statusPublished - 2018


  • accentuated Cupids bow
  • adolescent
  • adult
  • ANKRD11 gene
  • anteverted nostril
  • Apgar score
  • Article
  • birth weight
  • body height
  • bone malformation
  • bone radiography
  • brachydactyly
  • broad bushy eyebrow
  • case report
  • clinical article
  • clinical feature
  • developmental delay
  • disorders of higher cerebral function
  • elongated coccyx
  • epicanthus
  • exon
  • face dysmorphia
  • face malformation
  • father
  • female
  • gene
  • gene mutation
  • genetic association
  • genetic variability
  • gestational age
  • head circumference
  • human
  • hypertelorism
  • intron
  • karyotype
  • KBG syndrome
  • language delay
  • long palpebral fissure
  • male
  • MASP1 gene
  • molecular genetics
  • mother
  • peculiar calcaneus malformation
  • phenotype
  • prepuberty
  • priority journal
  • prominent coccyx
  • psychomotor development
  • SH3PXD2B gene
  • short stature
  • skinfold
  • special education
  • vaginal delivery


Dive into the research topics of 'Prominent and elongated coccyx, a new manifestation of KBG syndrome associated with novel mutation in ANKRD11'. Together they form a unique fingerprint.

Cite this