Junctional epidermolysis bullosa in the Middle East: clinical and genetic studies in a series of consanguineous families.
BACKGROUND
Junctional epidermolysis bullosa (JEB) is a group of inherited blistering diseases characterized by epidermal-dermal separation resulting from mutations that affect the function of critical components of the basement membrane zone. This group of autosomal recessive diseases is especially prevalent in regions where consanguinity is common, such as the Middle East. However, the clinical and genetic epidemiology of JEB in this region remains largely unexplored.


OBJECTIVE
The aim of the present study was to assess a series of consanguineous JEB families originating from the Middle East.


METHODS
We identified 7 families referred to us between 1998 and 1999 and originating from the United Arab Emirates, Saudi Arabia, Sudan, Yemen, and Israel. Histologic, immunofluorescence, and electron microscopy studies were performed to direct the subsequent molecular analysis. DNA obtained from all family members was amplified by means of polymerase chain reaction and analyzed by conformation-sensitive gel electrophoresis with subsequent direct sequencing.


RESULTS
In 6 families presenting with the clinical and histologic features distinctive for JEB, mutations in genes encoding 1 of the 3 subunit polypeptides of laminin-5 were identified. Two families each had mutations in LAMB3, 2 in LAMA3, and 2 in LAMC2. Out of 7 distinct mutations, 5 were novel and 2 were recurrent. No relationship was found between the presence of nonsense/frameshift mutations in laminin-5 genes and perinatal mortality, contradicting a major genotype-phenotype correlation previously reported in the European and US literature. Similarly, none of the recurrent LAMB3 hot spot mutations previously described in other populations was found in our series. Finally, in a family with the clinical diagnosis of generalized atrophic benign epidermolysis bullosa, a homozygous non-sense mutation in Col17A1 gene (encoding the BPAG2 antigen) was identified.


CONCLUSIONS
The present report suggests (1) the existence of a unique spectrum of mutations in the Middle East populations and (2) the need for the implementation of a diagnostic strategy tailored to the genetic features of JEB in this region.
Nakano
Aoi
A
Department of Dermatology and Cutaneous Biology, Jefferson Medical College and Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA.
Lestringant
Gilles G
GG
Paperna
Tamar
T
Bergman
Reuven
R
Gershoni
Ruth
R
Frossard
Philippe
P
Kanaan
Moien
M
Meneguzzi
Guerrino
G
Richard
Gabriele
G
Pfendner
Ellen
E
Uitto
Jouni
J
Pulkkinen
Leena
L
Sprecher
Eli
E
D001324:Autoantigens / Q000235:genetics; D002352:Carrier Proteins; D015815:Cell Adhesion Molecules / Q000235:genetics; D003094:Collagen / Q000235:genetics; D003241:Consanguinity; D003598:Cytoskeletal Proteins; D000071821:Dystonin; D016109:Epidermolysis Bullosa, Junctional / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008877:Middle East; D009154:Mutation; D009419:Nerve Tissue Proteins; D024041:Non-Fibrillar Collagens; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012867:Skin / Q000473:pathology; D000097794:Kalinin; D000097805:Collagen Type XVII
D001324:Autoantigens; D002352:Carrier Proteins; D015815:Cell Adhesion Molecules; D003094:Collagen; D003598:Cytoskeletal Proteins; D000071821:Dystonin; D009419:Nerve Tissue Proteins; D024041:Non-Fibrillar Collagens; D000097794:Kalinin; D000097805:Collagen Type XVII; C486268:DST protein, human