Alternative titles; symbols
SNOMEDCT: 254193007, 399971009, 724225008, 79855003; ORPHA: 251393, 79402, 79405; DO: 0060738;
| Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
Gene/Locus |
Gene/Locus MIM number |
|---|---|---|---|---|---|---|
| 1q32.2 | Epidermolysis bullosa, junctional 1A, intermediate | 226650 | Autosomal recessive | 3 | LAMB3 | 150310 |
A number sign (#) is used with this entry because of evidence that intermediate junctional epidermolysis bullosa 1A (JEB1A) is caused by homozygous or compound heterozygous mutation in the LAMB3 gene (150310) on chromosome 1q32.
Intermediate junctional epidermolysis bullosa 1A (JEB1A) is an autosomal recessive blistering disease of skin and mucous membranes. Generalized trauma-induced blistering occurs from birth. Blistering is less severe than in severe JEB (see 226700), usually without the tendency for developing chronic granulation tissue. The plane of skin cleavage is through the lamina lucida of the cutaneous basement membrane zone. Nail dystrophy or loss and dental enamel defects are present. Scarring or nonscarring alopecia and diffuse hair loss may occur (summary by Has et al., 2020). Blistering does not affect the life span of affected individuals (Pulkkinen and Uitto, 1998; Sybert, 2010).
Genetic Heterogeneity of Junctional Epidermolysis Bullosa
Another form of JEB that is caused by mutation in the LAMB3 gene is severe JEB1B (226700).
Forms of JEB caused by mutation in the LAMA3 gene (600805) are intermediate JEB2A (619783), severe JEB2B (619784), and laryngoonychocutaneous JEB2C (245660).
Forms of JEB caused by mutation in the LAMC2 gene (150292) are intermediate JEB3A (619785) and severe JEB3B (619786).
Intermediate JEB4 (619787) is caused by mutation in the COL17A1 gene (113811).
Forms of JEB caused by mutation in the ITGB4 gene (147557) are intermediate JEB5A (619816) and JEB with pyloric atresia (JEB5B; 226730).
Another form of JEB that includes pyloric atresia (JEB6; 619817) is caused by mutation in the ITGA6 gene (147556).
JEB with interstitial lung disease and nephrotic syndrome (JEB7; 614748), also known as interstitial lung disease, nephrotic syndrome, and epidermolysis bullosa (ILNEB), is caused by mutation in the ITGA3 gene (605025).
Reviews
Pulkkinen and Uitto (1999) reviewed the pathophysiology and phenotypic and genetic heterogeneity of epidermolysis bullosa.
Junctional epidermolysis bullosa is an autosomal recessive disorder characterized by skin blistering with a plane of cleavage through the lamina lucida of the cutaneous basement membrane. The severity varies considerably across 2 major subtypes, severe (previously known as generalized severe or Herlitz type) and intermediate (previously known as generalized intermediate or non-Herlitz type). The severe subtype is associated with death in the first 6 to 24 months of life. Other JEB subtypes are more rare, are clinically and genetically heterogeneous, and include several syndromic disorders (summary by Has et al., 2020).
Other names for intermediate JEB include progressive JEB, generalized JEB mitis, epidermolysis bullosa atrophicans generalisata mitis, nonlethal JEB, and 'Disentis type' of JEB, from the place of birth of a patient in Switzerland (Hashimoto et al., 1976).
Fine et al. (2000, 2008) proposed classification of the different forms of JEB into 'Herlitz' and 'non-Herlitz' types based on severity; the Herlitz type is more severe and often results in early death.
The term 'generalized atrophic benign epidermolysis bullosa' (GABEB) was a previous designation (Hintner and Wolff, 1982) for a non-Herlitz JEB subtype characterized by healing of blisters with atrophic scarring, nail dystrophy and loss, enamel hypoplasia and dental abnormalities, alopecia and sparsity of body hair, and characteristic pigmented melanocytic nevoid lesions. Although mutations in COL17A1 (113811) were identified in most cases designated GABEB (see JEB4, 619787), mutations in LAMB3 were identified in some cases (Mellerio et al., 1998).
In a report of a consensus meeting, Fine et al. (2000) stated that the term 'GABEB' is an inaccurate term to describe this disorder and suggested the term 'non-Herlitz type of junctional epidermolysis bullosa.' Fine et al. (2000, 2008) also eliminated the term 'hemidesmosomal,' which had previously been proposed for some forms of JEB (Uitto et al., 1997).
Sybert (2010) pointed out that the term 'benign' is legitimately applied to non-Herlitz (intermediate) JEB only in perspective to the lethality of the Herlitz form. Despite the high likelihood of survival beyond infancy, the burden of intermediate JEB is significant.
Hashimoto et al. (1976) observed this disorder in 3 offspring of a first-cousin marriage and named for Disentis, the place of birth of the patients. The proband was a 38-year-old man with extensive blistering. He also had 2 sibs who had died from blistering in the first days of life. Electron microscopy showed reduced or absent hemidesmosomes. Ridley and Levy (1968) observed survival of a possible case of the same condition to age 35 years.
Marras et al. (1984) emphasized the frequent occurrence of amniotic band constriction with epidermolysis bullosa. During a 10-year period at their institute, 8 newborns were hospitalized and 3 of these had associated anomalies due to amniotic band constriction. One of them had epidermolysis bullosa-pyloric atresia association. The 8 patients represented several different types of EB (Gedde-Dahl, 1981).
Bircher et al. (1993) reported a Swiss family in which 2 brothers and a sister demonstrated dystrophy of the nails, nonscarring blistering of skin, mild skin atrophy, hypodontia, and dental caries from school age. Light microscopy showed subepidermal blistering. Indirect immunofluorescence staining of a fresh spontaneous blister showed that the bullous pemphigoid antigens (DST, 113810 and COL17A1, 113811) and several forms of laminin were localized to the blister roof, and collagen IV (see, e.g., COL4A3, 120070) and collagen VII (see, e.g., COL7A1, 120120) to the blister base, indicating junctional splitting. Electron microscopy showed a normal dermoepidermal junction zone, including normal hemidesmosomes. There were no deposits of electron-dense amorphous material. Bircher et al. (1993) tabulated reported cases, including their 3 cases, and identified 18 patients from 10 families.
McGrath et al. (1995) reported 3 brothers with non-Herlitz JEB and mutation in the LAMB3 gene who were examined in their thirties. All had a history of generalized trauma-induced blistering from birth, which particularly affected the lower legs. Excellent clinical photographs were provided which showed, among other features, dystrophic changes of the fingernails and toenails with only a small amount of residual nail plate, abnormal dentition with extensive enamel hypoplasia, focal pitting, and discoloration, and marked loss of eyelashes with mild scarring of the lower lid margin. Patchy atrophic alopecia and sparse secondary sexual hair were also found.
Posteraro et al. (1998) studied a 5-year-old boy, the child of healthy nonconsanguineous parents, with intermediate JEB and mutation in the LAMB3 gene. Generalized trauma-induced skin blistering had been present from birth and affected mainly extremities and face. Blisters healed without scarring but with some hyperpigmentation and atrophy. Finger- and toenail dystrophy was present, but growth, teeth, mucosae, and hair were normal. Diagnosis of JEB was confirmed by electron microscopy, which showed skin cleavage within the lamina lucida as well as slightly hypoplastic hemidesmosomes.
Pulkkinen and Uitto (1998) studied 2 sibs, a woman and her younger brother, with nonlethal JEB and mutation in the LAMB3 gene. At age 27, the woman had widespread blistering on torso and extremities, with a history of corneal erosions and scarring. No blistering was present in the mouth, and hair was normal without scarring alopecia. She needed full dentures at 16 years of age due to severe caries resulting from extensive enamel hypoplasia. Additionally she had mitral valve prolapse and Wolff-Parkinson-White syndrome (see 194200). Her younger brother was very similarly affected; parents and a younger sister were unaffected.
Recessive Junctional Epidermolysis Bullosa Inversa
Junctional EB 'inversa' refers to a different pattern of skin involvement, involving intertriginous zones (Fine et al., 2008). Ridley (1977) reported a 55-year-old English woman with scattered blisters since birth with significant involvement of the genitocrural area. Histologic examination showed subepidermal lesions consistent with junctional cleavage. She also had corneal abrasions, mouth ulcerations, and enamel hypoplasia.
Gedde-Dahl et al. (1994) reported 4 Scandinavian families with autosomal recessive inheritance of junctional epidermolysis bullosa inversa; some had been reported by Gedde-Dahl (1971). Linkage analysis of 3 informative families identified linkage to a polymorphism in intron 20 of the laminin gamma-1 gene (LAMC1; 150290) on chromosome 1q31 (lod score of 1.65). All 4 patients of these families were homozygous for a 146-bp LAMC1 allele present on only 5% of random Norwegian chromosomes. A daughter of a deceased patient in a fourth family was found to carry the same 146-bp allele. The very strong association confirmed that the disease locus, which the authors termed 'EBR2A,' was at or closely linked to 1q31. Families with other clinical variants of JEB did not appear to be linked to or associated with this locus. However, the authors noted that LAMC2, which is involved in the Herlitz type of junctional epidermolysis bullosa, is located near the LAMC1 gene and may be the gene responsible. Gedde-Dahl et al. (1994) stated the English patient reported by Ridley (1977) was clinically indistinguishable from the Norwegian JEB-I patients and suggested that the Norwegian EBR2A allele may have been brought to England by the Vikings.
The transmission pattern of JEB1A in the family reported by McGrath et al. (1995) was consistent with autosomal recessive inheritance.
Epidemiologic data indicate that JEB is less common than either the simplex (see 131760) or dystrophic (see 226600) forms of epidermolysis bullosa (summary by Has et al., 2020).
Sybert (2010) pointed out that intermediate JEB, severe JEB (see 226700), severe epidermolysis bullosa simplex (EBS) Koebner (see 131900) or Dowling-Meara (see 131760), and recessive dystrophic epidermolysis bullosa (RDEB; 226600) can appear with identical clinical features at birth. Of intermediate versus severe JEB, she noted 'The diagnostic discriminator is time.'
Sybert (2010) stated that in survivors of severe JEB, the presence of granulation tissue around the nose may serve to distinguish their disorder from intermediate JEB.
Mutations in the LAMB3 Gene
In 3 brothers with non-Herlitz JEB, McGrath et al. (1995) identified compound heterozygosity for 2 mutations in the LAMB3 gene: a nonsense (150310.0003) and a missense (150310.0006) mutation.
In a 5-year-old boy with nonlethal JEB, Posteraro et al. (1998) identified compound heterozygosity for mutations in the LAMB3 gene, a single-base deletion (c.904delT; 150310.0005) and a missense mutation (E210K; 150310.0006).
In 3 patients with nonlethal JEB, Mellerio et al. (1998) identified compound heterozygosity for the E210K mutation in LAMB3 and different nonsense mutations in the other allele (see, e.g., 150310.0003).
Pulkkinen and Uitto (1998) detected compound heterozygosity for premature termination mutations in 2 sibs with nonlethal JEB, the recurrent R235X mutation (150310.0001) and a 5-basepair deletion (150310.0010). This report represented the first exception to the general rule that mutations leading to premature termination codons on both alleles result in Herlitz (lethal) JEB, whereas in nonlethal variants at least one allele has a missense or in-frame exon skip mutation.
Revertant Mosaicism
Pasmooij et al. (2007) described 2 unrelated non-Herlitz junctional EB patients with revertant mosaicism. The first was a 46-year-old man who was compound heterozygous for germline R635X (150310.0001) and E210K (150310.0006) mutations in the LAMB3 gene and who had reversion to clinically unaffected skin on his left lower leg. The authors identified 2 different somatic second-site mutations (150310.0012 and 150310.0013) on the E210K allele in 2 different lower leg biopsies; the compensatory mutations were not found in fibroblasts taken from the same biopsies or in more than 80 control subjects. Reversion of the inherited R635X mutation did not occur. The second patient was a 64-year-old man who was homozygous for an E210K germline mutation in LAMB3 and who had reversion to clinically normal skin at his upper arms, shoulders, and chest. Pasmooij et al. (2007) identified 3 different somatic second-site mutations on 1 of the E210K alleles in 3 different biopsies of reverted skin (150310.0014-150310.0016, respectively). The second-site mutations were not found in more than 160 control chromosomes. Analysis of mRNA from the newly normal skin in both patients revealed that all of the second-site mutations had effects at the RNA level.
Jonkman and Pasmooij (2009) analyzed data from 20 patients with non-Herlitz junctional EB, 14 of whom had type XVII collagen deficiency due to mutant COL17A1 (113811) and 6 of whom had laminin-beta-3 deficiency due to mutant LAMB3. The authors found an unexpectedly high number of patients with revertant patches including 5 (36%) of 14 patients with collagen deficiency and 2 (33%) of 6 with laminin deficiency, as reflected by the reexpression of the deficient protein on immunofluorescence-antigen mapping of skin-biopsy specimens. In addition, at least 6 of the 7 patients with revertant mosaicism had multiple patches, each caused by a different molecular event. Jonkman and Pasmooij (2009) suggested that revertant somatic mosaicism should be considered when a patient has an atypical phenotype.
Nakano et al. (2002) studied the mutational differences between the Herlitz and non-Herlitz forms of junctional EB. They examined a cohort of 27 families, 15 with Herlitz and 12 with non-Herlitz junctional EB, for mutations in the candidate genes LAMA3, LAMB3, and LAMC2. The largest number of mutations for both forms occurred in the LAMB3 gene. Most cases with Herlitz junctional EB harbored premature termination codon (PTC) mutations in both alleles. In non-Herlitz cases, the PTC mutation was frequently associated with a missense mutation or a putative splicing mutation in trans, i.e., the patient was a compound heterozygote.
Varki et al. (2006) performed genetic analysis in 234 patients diagnosed with junctional or hemidesmosomal EB and identified a mutation in at least 1 allele in 209 cases (89.3%); in that cohort of 209 patients, 393 (94.0%) mutant alleles were discovered among the total 418 alleles studied. The majority (70.4%) of the mutations occurred in LAMA3, LAMB3, and LAMC2, the 3 genes that encode the subunits of laminin-5, and most of those (80.1%) were in LAMB3. Varki et al. (2006) reviewed the clinical and molecular heterogeneity of the junctional and hemidesmosomal subtypes of EB, discussed exceptions to the general rules on genotype-phenotype correlations, and noted unusual phenotypes and genetics observed in patients and families with EB.
Gene Therapy
Posteraro et al. (1998) described a patient with a nonlethal variant of junctional EB who was found to be a compound heterozygote for mutations affecting the LAMB3 gene (see 150310.0005 and 150310.0006). Mavilio et al. (2006) transduced epidermal cells from this patient with a retroviral vector expressing LAMB3 and transplanted 9 genetically corrected cultured epidermal skin grafts onto the anterior upper regions of the patient's legs, where he had suffered several infected nonhealing lesions. Synthesis and proper assembly of normal levels of functional LAM5 were observed, together with the development of a firmly adherent epidermis that remained stable during 1 year of follow-up in the absence of blisters, infections, inflammation, or immune response. Retroviral integration site analysis indicated that the regenerated epidermis was maintained by a defined repertoire of transduced stem cells. Mavilio et al. (2006) concluded that ex vivo gene therapy of JEB is feasible and can lead to full functional correction of the disease.
Bircher, A. J., Lang-Muritano, M., Pfaltz, M., Bruckner-Tuderman, L. Epidermolysis bullosa junctionalis progressiva in three siblings. Brit. J. Derm. 128: 429-435, 1993. [PubMed: 8494757] [Full Text: https://doi.org/10.1111/j.1365-2133.1993.tb00204.x]
Fine, J.-D., Eady, R. A. J., Bauer, E. A., Bauer, J. W., Bruckner-Tuderman, L., Heagerty, A., Hintner, H., Hovnanian, A., Jonkman, M. F., Leigh, I., McGrath, J. A., Mellerio, J. E., Murrell, D. F., Shimizu, H., Uitto, J., Vahlquist, A., Woodley, D., Zambruno, G. The classification of inherited epidermolysis bullosa (EB): report of the Third International Consensus Meeting on diagnosis and classification of EB. J. Am. Acad. Derm. 58: 931-950, 2008. [PubMed: 18374450] [Full Text: https://doi.org/10.1016/j.jaad.2008.02.004]
Fine, J.-D., Eady, R. A. J., Bauer, E. A., Briggaman, R. A., Bruckner-Tuderman, L., Christiano, A., Heagerty, A., Hintner, H., Jonkman, M. F., McGrath, J., McGuire, J., Moshell, A., Shimizu, H., Tadini, G., Uitto, J. Revised classification system for inherited epidermolysis bullosa: report of the Second International Consensus Meeting on diagnosis and classification of epidermolysis bullosa. J. Am. Acad. Derm. 42: 1051-1066, 2000. [PubMed: 10827412]
Gedde-Dahl, T., Jr., Dupuy, B. M., Jonassen, R., Winberg, J.-O., Anton-Lamprecht, I., Olaisen, B. Junctional epidermolysis bullosa inversa (locus EBR2A) assigned to 1q31 by linkage and association of LAMC1. Hum. Molec. Genet. 3: 1387-1391, 1994. [PubMed: 7987320] [Full Text: https://doi.org/10.1093/hmg/3.8.1387]
Gedde-Dahl, T., Jr. Epidermolysis Bullosa: A Clinical, Genetic and Epidemiological Study. Baltimore: Johns Hopkins Press (pub.) 1971. Pp. 117-119.
Gedde-Dahl, T., Jr. Sixteen types of epidermolysis bullosa: on the clinical discrimination, therapy and prenatal diagnosis. Acta Derm. Venereol. Suppl. (Stockh.) 95: 74-87, 1981. [PubMed: 6953718]
Has, C., Bauer, J. W., Bodemer, C., Bolling, M. C., Bruckner-Tuderman, L., Diem, A., Fine, J. D., Heagerty, A., Hovnanian, A., Marinkovich, M. P., Martinez, A. E., McGrath, J. A., and 10 others. Consensus reclassification of inherited epidermolysis bullosa and other disorders with skin fragility. Brit. J. Derm. 183: 614-627, 2020. [PubMed: 32017015] [Full Text: https://doi.org/10.1111/bjd.18921]
Hashimoto, I., Schnyder, U. W., Anton-Lamprecht, I. Epidermolysis bullosa hereditaria with junctional blistering in an adult. Dermatologica 152: 72-86, 1976. [PubMed: 939338] [Full Text: https://doi.org/10.1159/000251166]
Hintner, H., Wolff, K. Generalized atrophic benign epidermolysis bullosa. Arch. Derm. 118: 375-384, 1982. [PubMed: 7092249]
Jonkman, M. F., Pasmooij, A. M. G. Revertant mosaicism: patchwork in the skin. (Letter) New Eng. J. Med. 360: 1680-1682, 2009. [PubMed: 19369679] [Full Text: https://doi.org/10.1056/NEJMc0809896]
Marras, A., Dessi, C., Macciotta, A. Epidermolysis bullosa and amniotic bands. (Letter) Am. J. Med. Genet. 19: 815-817, 1984. [PubMed: 6517104] [Full Text: https://doi.org/10.1002/ajmg.1320190423]
Mavilio, F., Pellegrini, G., Ferrari, S., Di Nunzio, F., Di Iorio, E., Recchia, A., Maruggi, G., Ferrari, G., Provasi, E., Bonini, C., Capurro, S., Conti, A., Magnoni, C., Giannetti, A., De Luca, M. Correction of junctional epidermolysis bullosa by transplantation of genetically modified epidermal stem cells. Nature Med. 12: 1397-1402, 2006. [PubMed: 17115047] [Full Text: https://doi.org/10.1038/nm1504]
McGrath, J. A., Pulkkinen, L., Christiano, A. M., Leigh, I. M., Eady, R. A. J., Uitto, J. Altered laminin 5 expression due to mutations in the gene encoding the beta-3 chain (LAMB3) in generalized atrophic benign epidermolysis bullosa. J. Invest. Derm. 104: 467-474, 1995. [PubMed: 7706760] [Full Text: https://doi.org/10.1111/1523-1747.ep12605904]
Mellerio, J. E., Eady, R. A. J., Atherton, D. J., Lake, B. D., McGrath, J. A. E210K mutation in the gene encoding the beta-3 chain of laminin-5 (LAMB3) is predictive of a phenotype of generalized atrophic benign epidermolysis bullosa. Brit. J. Derm. 139: 325-331, 1998. [PubMed: 9767254] [Full Text: https://doi.org/10.1046/j.1365-2133.1998.02377.x]
Nakano, A., Chao, S.-C., Pulkkinen, L., Murrell, D., Bruckner-Tuderman, L., Pfendner, E., Uitto, J. Laminin 5 mutations in junctional epidermolysis bullosa: molecular basis of Herlitz vs non-Herlitz phenotypes. Hum. Genet. 110: 41-51, 2002. [PubMed: 11810295] [Full Text: https://doi.org/10.1007/s00439-001-0630-1]
Pasmooij, A. M. G., Pas, H. H., Bolling, M. C., Jonkman, M. F. Revertant mosaicism in junctional epidermolysis bullosa due to multiple correcting second-site mutations in LAMB3. J. Clin. Invest. 117: 1240-1248, 2007. [PubMed: 17476356] [Full Text: https://doi.org/10.1172/JCI30465]
Posteraro, P., Sorvillo, S., Gagnoux-Palacios, L., Angelo, C., Paradisi, M., Meneguzzi, G., Castiglia, D., Zambruno, G. Compound heterozygosity for an out-of-frame deletion and a splice site mutation in the LAMB3 gene causes nonlethal junctional epidermolysis bullosa. Biochem. Biophys. Res. Commun. 243: 758-764, 1998. [PubMed: 9501007] [Full Text: https://doi.org/10.1006/bbrc.1998.8180]
Pulkkinen, L., Uitto, J. Heterozygosity for premature termination codon mutations in LAMB3 in siblings with non-lethal junctional epidermolysis bullosa. J. Invest. Derm. 111: 1244-1246, 1998. [PubMed: 9856855] [Full Text: https://doi.org/10.1046/j.1523-1747.1998.00399.x]
Pulkkinen, L., Uitto, J. Mutation analysis and molecular genetics of epidermolysis bullosa. Matrix Biol. 18: 29-42, 1999. [PubMed: 10367729] [Full Text: https://doi.org/10.1016/s0945-053x(98)00005-5]
Ridley, C. M., Levy, L. S. Epidermolysis bullosa and amyloidosis: a case report. Trans. St. Johns Hosp. Derm. Soc. 54: 75-82, 1968. [PubMed: 4301372]
Ridley, C. M. Epidermolysis bullosa with unusual features: inversa type. Proc. R. Soc. Med. 70: 576-577, 1977. [PubMed: 918074]
Sybert, V. P. Genetic Skin Disorders. (2nd ed.) New York: Oxford Univ. Press (pub.) 2010. Pp. 155-163.
Uitto, J., Pulkkinen, L., McLean, W. H. I. Epidermolysis bullosa: a spectrum of clinical phenotypes explained by molecular heterogeneity. Molec. Med. Today 3: 457-465, 1997. [PubMed: 9358473] [Full Text: https://doi.org/10.1016/s1357-4310(97)01112-x]
Varki, R., Sadowski, S., Pfendner, E., Uitto, J. Epidermolysis bullosa. I. Molecular genetics of the junctional and hemidesmosomal variants. J. Med. Genet. 43: 641-652, 2006. [PubMed: 16473856] [Full Text: https://doi.org/10.1136/jmg.2005.039685]