Mandibuloakral displazi: Vaka sunumu ve laminopatilere genel bakış

Mandibuloakral displazi postnatal başlangıçlı büyüme geriliği, dismorfik yüz bulguları, iskelet bulguları, cilt bulguları ve metabolik bozukluklar ile karakterize ender görülen otozomal resesif sendromlardan biridir. Hastalığın tipik özelliği, vakaların doğumda tamamen normal olması ve yaş ilerledikçe büyüme geriliği, dismorfizm ve diğer bulguların tabloya eklenmesidir. Mandibuloakral displazi yağ dağılım paternine göre tip A (MADA) ve tip B (MADB) olmak üzere iki tipe ayrılır. MADA’da ekstremitelerde yaygın yağ doku kaybı ve yüz, boyun ve gövdede yağ dokusu artışı vardır. MADB’de ise tüm vücutta yaygın yağ doku kaybı vardır. Hastalığa neden olan genler lamin A/C (LMNA) ve çinko metalloproteinaz (ZMPSTE24) olup, her iki gende, A tipi laminlerin oluşumunda görevlidir. ZMPSTE24 geni prelamin A’nın post-translasyonel modifikasyonunda rol alır. LMNA genindeki bozukluklara primer laminopatiler, ZMPSTE24 genindeki bozukluklara sekonder laminopatiler denir. Günümüze kadar en az yedi otozomal dominant ve dört otozomal resesif hastalıkta primer laminopati tanımlanmıştır. Sekonder laminopatiler ise iki otozomal resesif hastalıkta, MADB ve restriktif dermopati, gözlenmiştir. Belirgin büyüme-gelişme geriliği ve dismorfik bulguları nedeniyle kliniğimize başvuran ve ciltaltı yağ doku kaybı yaygın olması, klinik bulguların 2,5 yaşında başlaması ve böbrek tutulumu olması nedeniyle klinik MAD tip B tanısı alan 14 yaşında bir erkek vaka klinik ve laboratuvar bulguları ile sunulmuştur.

Mandibuloacral dysplasia: Case report and review of laminopathies

Mandibuloacral dysplasia is a rare autosomal recessive disorder characterized by postnatal growth retardation, dysmorphic facial features, skeletal findings, skin findings and metabolic changes. As the typical feature of the disease, patients are normal at birth and as they get older growth retardation, dysmorphism and other accompanying findings contribute to the clinical picture. Mandibuloacral dysplasia is subdivided into two groups due to the fat distribution pattern as type A (MADA) and type B (MADB). In MADA fat tissue is diffusely lost at extremities and increased at face, neck and body. In MADB there is diffuse fat tissue loss all over the body. Disease causing genes, lamin A/C (LMNA) and zinc metalloproteinase (ZMPSTE24), are responsible for lamin A formation. ZMPSTE24 gene has a role in prelamin A`s postranslational modification. Defects in LMNA gene are named as primary laminopathy and defects in ZMPSTE24 gene are referred as secondary laminopathy. Up to date seven autosomal dominant and four autosomal recessive primary laminopathies have been described. Secondary laminopathies are observed in two autosomal recessive, MADB and restrictive dermatopathy, disorders. We here report a 14-years old male patient`s clinical and laboratory findings who was referred to our outpatient clinics for prominent growth retardation and dysmorphic features and clinically diagnosed as MADB due to diffuse fat tissue loss, age of onset of symptoms being 2,5 years and renal findings.

Kaynakça

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Kaynak Göster