The intracellular retention of mutant cartilage matrix proteins and pathological endoplasmic reticulum (ER) stress disrupts ossification and has been identified as a shared disease mechanism in a range of skeletal dysplasias including short limbed-dwarfism, multiple epiphyseal dysplasia type 5 (EDM5). Although targeting ER stress is an attractive avenue for treatment and has proven successful in the treatment of a related skeletal dysplasia, to date no drugs have proven successful in reducing ER stress in EDM5 caused by the retention of mutant matrilin-3. Our exciting findings show that by using our established luciferase ER stress screening assay, we can identify a "natural" chemical, curcumin, which is able to reduce pathological ER stress in a cell model of EDM5 by promoting the proteasomal degradation mutant matrilin-3. Therefore, this is an important in vitro study in which we describe, for the first time, the success of a naturally occurring chemical as a potential treatment for this currently incurable rare skeletal disease. As studies show that curcumin can be used as a potential treatment for range of diseases in vitro, current research is focused on developing novel delivery strategies to enhance its bioavailability. This is an important and exciting area of research that will have significant clinical impact on a range of human diseases including the rare skeletal disease, EDM5.

Multiple epiphyseal dysplasia, which affects the epiphysis of long bones, can show autosomal dominant and autosomal recessive inheritance patterns (Ballhausen et al., 2003 [1]). The symptoms typically appear in childhood, although they sometimes do not show symptoms until adulthood. The goals of treatment in children are to prevent the early onset of osteoarthritis, improve function, and educate patients and their families about the natural history and genetic basis of the disease. Some patients present to the clinic with only non-healing and unidentified joint pain. Although multiple epiphyseal dysplasia type 5 is a rare disease with autosomal dominant inheritance in general, it can also be observed with de novo mutation, although very rarely, without a family history. 7-years-old male patient was admitted to our orthopedics outpatient clinic with complaints of joint pain, fatigue, and pain in the knees and ankles that had lasted for about 3 years. He had epicanthus, left hemifacial microsomia, and metacarpophalangeal joint laxity. The arm was proportional to the body. In the laboratory, there was no obvious finding other than vitamin D deficiency. The epiphyses, especially in the ankle, were dysplasic on Xray. After genetic tests we detected multiple epiphyseal dysplasia type 5, with de novo mutation, without family histories. Multiple epiphyseal dysplasia type 5, which is usually an autosomal dominant disease (Ballhausen et al., 2003 [1]) characterized by normal height; it is seen due to heterozygous mutation of matrilin-3 gene (MATN3) at 2p24.1 location. Early-onset osteoarthritis, multiple epiphyseal dysplasia, arthralgia, small proximal femoral epiphyses, wide and short femoral neck, coxa vara, high greater trochanter, small, irregular epiphyses (distal femoral, proximal tibia, distal radius, distal ulna), mild metaphyseal irregularities (distal femoral, proximal tibia, proximal humeri, distal radius, distal ulna), genu valgum may accompany. In hands; small, irregular epiphyses (first metacarpal), delayed carpal ossification may be seen. Delayed tarsal ossification can be observed in the feet. On the other hand, some patients present to the clinic with only non-healing and unidentified joint pain. Although multiple epiphyseal dysplasia type 5 a rare disease with autosomal dominant inheritance in general, it can also be observed like our case with de novo mutation, although very rarely, without a family history. Multiple epiphyseal dysplasia type 5 is a rare disease. It should be kept in mind that skeletal dysplasia should also be evaluated, although it is rarely seen in patients with persistent joint pain. Thus, we can both slow down the progression with early diagnosis of the patient and minimize the early surgical requirements.