Clinical and genetic analysis of two Chinese infants with Mabry syndrome

Brain Dev. 2016 Oct;38(9):807-18. doi: 10.1016/j.braindev.2016.04.008. Epub 2016 May 10.


Objective: Hyperphosphatasia mental retardation syndrome (Mabry syndrome) is an autosomal recessive disorder. We aim to analyze two Chinese patients diagnosed as Mabry syndrome.

Methods: The clinical manifestations, diagnosis and treatment were observed in two patients. Genetic analysis including PIGV and PIGO was examined.

Results: Two patients were diagnosed as Mabry syndrome clinically and genetically. Developmental delay, hyperphosphatasia and seizures were presented in both of them. Typical facial dysmorphism and hypoplastic terminal phalanges were only found in one. Some novel presentations including congenital laryngeal cartilage softening, inguinal hernia, broken palmprint, optic atrophy and skeleton dysplasia such as carpal age delay and metaphysis anomalies were observed in two patients. Molecular genetic analysis revealed compound heterozygous mutations of PIGV or PIGO in our patients, including c.615C>G (p.Asn205Lys) and c.854A>G (p.Tyr285Cys) of PIGV in patient 1, and c.458T>C (p.Phe153Ser) and c.1355_1356del (p.Ala452Glyfs*52) of PIGO in patient 2. Additionally, a heterozygous c.2926G>A (Asp976Asn) of PCDH19 was identified in patient with PIGV mutations, the causative gene of Epilepsy and mental retardation limited to females (EFMR).

Conclusion: To our best knowledge, this is the first time to report Chinese patients diagnosed as Mabry syndrome. For the PCDH19 mutation in our patient carrying PIGV mutations, due to lacking characteristics of EFMR and the ambiguity results in pathogenicity analysis, we were not sure how much pathogenic role PCDH19 mutation shared with PIGV mutations in this disease. The novel mutations of PIGV and PIGO, and novel clinical manifestations reported here might expand the genotype and phenotype spectrum of Mabry syndrome.

Keywords: Cognitive disability; Hyperphosphatasia; PIGO gene; PIGV gene; Seizures.

Publication types

  • Case Reports

MeSH terms

  • Abnormalities, Multiple / diagnosis
  • Abnormalities, Multiple / genetics*
  • Abnormalities, Multiple / physiopathology*
  • Abnormalities, Multiple / therapy
  • Asian People
  • Brain / diagnostic imaging
  • Brain / physiopathology
  • Cadherins / genetics
  • China
  • Diagnosis, Differential
  • Female
  • Humans
  • Infant
  • Intellectual Disability / diagnosis
  • Intellectual Disability / genetics*
  • Intellectual Disability / physiopathology*
  • Intellectual Disability / therapy
  • Male
  • Mannosyltransferases / genetics
  • Membrane Proteins / genetics
  • Mutation
  • Phenotype
  • Phosphorus Metabolism Disorders / diagnosis
  • Phosphorus Metabolism Disorders / genetics*
  • Phosphorus Metabolism Disorders / physiopathology*
  • Phosphorus Metabolism Disorders / therapy
  • Protocadherins


  • Cadherins
  • Membrane Proteins
  • PCDH19 protein, human
  • PIGO protein, human
  • Protocadherins
  • Mannosyltransferases
  • PIGV protein, human

Supplementary concepts

  • Hyperphosphatasia with Mental Retardation