The 3M syndrome
BEST PRACTICE & RESEARCH CLINICAL ENDOCRINOLOGY & METABOLISM
Authors: Huber, Celine; Munnich, Arnold; Cormier-Daire, Valerie
Abstract
3M syndrome (MIM 273750) is an autosomal recessive disorder characterized by pre- and post-natal growth retardation (<-4 SD), facial dysmorphism, large head circumference, normal intelligence and endocrine function. Skeletal changes include long slender tubular bones and tall vertebral bodies. There is no specific treatment. Uptill now, mutations in either CUL7 or OBSL1 genes have been identified in this rare disorder. There are no clinical or radiological differences between patients with CUL7 or OBSL1 mutations. CUL7 appears to be the major gene responsible for 3M syndrome accounting for 77.5% of cases while OBSL1 mutations accounts for 16.3%. A few patients have no mutations in these genes suggesting the involvement of a third gene. (C) 2010 Elsevier Ltd. All rights reserved.
Further expanding the mutational spectrum and investigation of genotype-phenotype correlation in 3M syndrome
AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Authors: Simsek-Kiper, Pelin Ozlem; Taskiran, Ekim; Kosukcu, Can; Arslan, Umut Ece; Cormier-Daire, Valerie; Gonc, Nazli; Ozon, Alev; Alikasifoglu, Ayfer; Kandemir, Nurgun; Utine, Gulen Eda; Alanay, Yasemin; Alikasifoglu, Mehmet; Boduroglu, Koray
Abstract
3M syndrome is characterized by severe pre- and postnatal growth retardation, typical facial features, and normal intelligence. Homozygous or compound heterozygous mutations in either CUL7, OBSL1, or CCDC8 have been identified in the etiology so far. Clinical and molecular features of 24 patients (23 patients and a fetus) from 19 unrelated families with a clinical diagnosis of 3M syndrome were evaluated and genotype-phenotype correlations were investigated with the use of DNA sequencing, chromosomal microarray, and whole exome sequencing accordingly. A genetic etiology could be established in 20 patients (n = 20/24, 83%). Eleven distinct CUL7 or OBSL1 mutations, among which eight was novel, were identified in 18 patients (n = 18/24, 75%). Ten patients had CUL7 (n = 10/18, 56%) while eight had OBSL1 (n = 8/18, 44%) mutations. Birth weight and height standard deviation scores at admission were significantly (p < 0.05) lower in patients with CUL7 mutation compared to that of patients with OBSL1 mutation. Two patients with a similar phenotype had a de novo 20p13p deletion involving BMP2. No genetic etiology could be established in four patients (n = 4/28, 17%). This study yet represents the largest cohort of 3M syndrome patients from a single center in Turkey. Microdeletions involving BMP2 may cause a phenotype similar to 3M syndrome with some distinctive features. Larger cohort of patients are required to establish genotype-phenotype correlations in 3M syndrome.