3M syndrome is a rare autosomal recessive disorder that combines intrauterine growth retardation (IUGR) and postnatal growth retardation. Additionally, this syndrome is characterized by dysmorphic facial features (large head, dolichocephaly, frontal bossing, a triangular face, long philtrum and hypoplastic midface) and certain radiological abnormalities. The latter includes slender long bones and ribs, foreshortened vertebral bodies, and small pelvis. The name of this disorder comes from the initials of the three researchers (Miller, McKusik and Malvaux) who first identified it.
The characteristic radiologic findings of 3M syndrome are used to rule out similar disorders such as Silver-Russel syndrome (SRS), particularly the lack of limb length asymmetry that is present in over half of those with autosomal recessive SRS. The severity of symptoms and physical features varies considerably from case to case. Prenatal diagnosis is possible by ultrasonography. Supplying growth hormone to patients can help to increase body height.
Al-Dosari et al. (2012) characterized a cohort of 14 patients 3M syndrome born to six consanguineous Saudi families (A-F). Genomic DNA analysis revealed that patients of families D and E shared a novel homozygous identical mutation of 1bp deletion in exon 3 of OBSL1 (c.1306del, p.Arg436Glyfs*14). The affected group included a 5.5-year-old girl and a 9-month-old boy from family D, who both received a diagnosis of severe intrauterine growth retardation, which persisted in the form of severe proportionate short stature postnatally. In family E, the index case was a 9.5-year-old girl of normal intelligence with severe proportionate short stature. Despite their typical and easily discernible clinical phenotype, all these patients have been extensively investigated for alternative causes of their short stature and received erroneous diagnoses. Al-Dosari et al. (2012) emphasized that increased awareness about this syndrome among pediatricians and endocrinologists is needed to avoid a costly and unnecessary diagnostic odyssey.