The clinical presentation of Dyggve-Melchior-Clausen syndrome (DMC), initially described approximately 50 years ago [1], is distinguished by a combination of several features that develop in early childhood [1] [2] [3] [4] [5] [6]:

• Skeletal changes - The most prominent feature of DMC syndrome is a very short stature, with standard deviation scores (SDS) reaching as low as -12.6 SD in some reports [1]. The upper part of the body seems to be more severely affected and a pigeon-shaped (or barrel) chest is one of the hallmarks of Dyggve-Melchior-Clausen syndrome [1]. Rhizomelic limb shortening is an accompanying feature [1] [3]. Lumbar lordosis, brachydactyly, and broad interphalangeal joints are seen in up to 100% of patients, whereas scoliosis, kyphosis, protrusion of the sternal bone, genu valgum or varum, and limited joint extension are other notable manifestations that develop in up to 50% of individuals [1] [6].
• Mental retardation - The second crucial feature of DMC syndrome is mental retardation, varying from moderate to severe [1].
• Craniofacial changes - Virtually all patients who suffer from DMC syndrome develop microcephaly and a disproportionate development of the skull and facial bones compared to the brain size [1] [5]. In addition, characteristic facial changes include a narrow forehead, thick lips, macrognathia, prominent ears, and macrostomia [1].

Other notable findings are a protruded abdomen and generalized hirsutism [1].

• Disproportionate Short Stature

  It is characterized by progressive spondyloepimetaphyseal dysplasia leading to disproportionate short stature, microcephaly, and coarse facies. [ncbi.nlm.nih.gov]

  Disproportionate short stature usually occurs after 18 months. Additional features may include a long skull, distinctive facial appearance, a protruding jaw, microcephaly, and claw-like hands. [rarediseases.info.nih.gov]

  By the age of 5 years, disproportionate short stature becomes evident. Joint mobility is somehow restricted. [egms.de]

• Broad Thumb

  Fig 2. - Hand of patient Mo. showing short broad thumbs. thigh. [healthdocbox.com]

• Barrel Chest

  This site is intended for healthcare professionals General Practice Notebook This dysplastic syndrome is characterised by: short stature short trunk barrel chest accentuated lumbar lordosis restricted joint mobility waddling gait in some families this [gpnotebook.co.uk]

  Clinically, thoracic deformities in the form of barrel chest become visible in the first 18 months of life. [accessanesthesiology.mhmedical.com]

• Normal Hearing

  Noteworthy features of normal hearing, normal teeth and a normal odontoid with no subsequent atlanto-axial instability, but microcephaly and mental sub-normality were notable in our present patient. [egms.de]

• Atlanto-Axial Instability

  The most notable radiographic findings are a lacy iliac crest apophysis, hip dysplasia, double vertebral hump, and odontoid hypoplasia with atlanto-axial instability. [ncbi.nlm.nih.gov]

  Noteworthy features of normal hearing, normal teeth and a normal odontoid with no subsequent atlanto-axial instability, but microcephaly and mental sub-normality were notable in our present patient. [egms.de]

• Prolapse

  […] disproportionate short stature, developmental delay, and severe ID with a novel frameshift mutation (c.1028_1056del29) leading to a premature stop codon, and the second patient with classical clinical and radiological features of DMC with mild ID and rectal prolapse [ncbi.nlm.nih.gov]

• Short Neck

  neck Decreased length of neck 0000470 Sloping forehead Inclined forehead Receding forehead [ more ] 0000340 Spinal canal stenosis Narrow spinal canal 0003416 5%-29% of people have these symptoms Attention deficit hyperactivity disorder Attention deficit [rarediseases.info.nih.gov]

  Difficult tracheal intubation is likely (even without atlantoaxial instability) because of the presence of a short neck, prominent, big jaws, macroglossia, and limited mouth opening. [accessanesthesiology.mhmedical.com]

  neck Spondyloepimetaphyseal dysplasia Thoracic kyphosis Waddling gait Wide pubic symphysis Based on the frequency of symptoms observed, the following information may be noted: Very frequently present symptoms in 80-99% of the cases: Abnormality of epiphysis [dovemed.com]

  He had a short neck, short trunk, flared nibs with a bulging sternum, and a thonacic kyphosis with dorsal lordosis. The large joints were enlarged. There was no hepatosplenomegaly and no genu valgum. [healthdocbox.com]

• Waddling Gait

  gait, and radiographic findings of irregular iliac crests and flattening of vertebral bodies; autosomal recessive inheritance. [medical-dictionary.thefreedictionary.com]

  This site is intended for healthcare professionals General Practice Notebook This dysplastic syndrome is characterised by: short stature short trunk barrel chest accentuated lumbar lordosis restricted joint mobility waddling gait in some families this [gpnotebook.co.uk]

• Shuffling Gait

  He has a short neck, thonacic kyphoscoliosis, protuberant abdomen, liver palpable 4 cm below the costal margin, normal sexual development, limitation of full extension of wrists, elbows, and knees, a waddling, shuffling gait, and short. broad thumbs [healthdocbox.com]

Because Dyggve-Melchior-Clausen syndrome is very rare, the diagnosis may be difficult to attain without a thorough diagnostic workup. Since affected children develop the typical clinical presentation in the first several years of life, the physician should first obtain a detailed patient history from the parents. The history should cover the onset of symptoms and their progression, as well as severity. The fact that many identified patients either come from consanguineous marriages or have first-degree relatives who already suffer from Dyggve-Melchior-Clausen syndrome makes a complete family history crucial for identifying a genetic background of the disease. As soon as clinical suspicion is raised, imaging studies should be employed. Plain radiography of the axial skeleton, the pelvis, and the limbs is the key step for determining the exact type of deformity [1] [3]. One of the most specific findings seen in this syndrome is the lace-like character of the iliac crests. Small iliac wings, bilateral hip dislocation, a widened pubic symphysis, acetabular hypoplasia, a wide sacroiliac joint and deformed femoral heads are other prominent findings in the hips in these patients [1] [3]. A barrel-shaped chest with broad ribs, platyspondyly, and a double-hump shape of the bone end-plates provide sufficient evidence to make a solid diagnosis of Dyggve-Melchior-Clausen syndrome [1] [3]. Genetic studies can be used as a definitive method, which confirm mutations of the dymeclin gene located on chromosome 18 [1] [2] [4] [5] [6].

1. Aglan MS, Temtamy SA, Fateen E, Ashour AM, Eldeeb K, Hosny GA. Dyggve–Melchior–Clausen syndrome: clinical, genetic, and radiological study of 15 Egyptian patients from nine unrelated families. J Child Orthop. 2009;3(6):451-458.
2. Dyggve HV, Melchior JC, Clausen J. Morquio-Ullrich’s disease: an inborn error of metabolism? Arch Dis Child. 1962;37:525–534.
3. Beighton P. Dyggve–Melchior–Clausen syndrome. J Med Genet. 1990;27:512–515.
4. Thauvin-Robinet C, El Ghouzzi V, Chemaitilly W, et al. Homozygosity mapping of a Dyggve–Melchior–Clausen syndrome gene to chromosome 18q21.1. J Med Genet. 2002;39:714–717.
5. Ehtesham N, Cantor RM, King LM, et al. Evidence that Smith–McCort dysplasia and Dyggve–Melchior–Clausen dysplasia are allelic disorders that result from mutations in a gene on chromosome 18q12. Am J Hum Genet. 2002;71:947–951.
6. Gupta V, Kohli A, Dewan. Dyggve melchior clausen syndrome. Indian Pediatr. 2010;47(11):973-975.