Prenatal diagnosis of epidermolysis bullosa dystrophica Hallopeau-Siemens with electron microscopy of fetal skin

Invasive prenatal diagnostic techniques

Subspecialization in fetal medicine has expanded the scope for obstetricians to investigate the fetus and its surrounding environment in greater detail. Of the advances in technology that have made this possible, ultrasonography is the most important. A high degree of skill is required if it is to be applied to the performance of invasive diagnostic techniques. These should be performed only in specialized centres with appropriate facilities and an adequate referral base. However, it is important for obstetricians to know what is possible in the field of prenatal diagnosis and therapy in order to give patients the best advice.

Prenatal diagnosis as a test for genodermatoses: its past, present and future

The prenatal diagnosis (PND) of severe hereditary skin diseases started in the early 1980s using fetal skin biopsy techniques based on ultrastructural and immunohistochemical abnormalities of the fetal skin. Recent success in identifying responsible genes and demonstrating mutations in such genes has set the stage for DNA-based PND in the 1990s. Common examples of skin conditions which can be prenatally diagnosed include epidermolysis bullosa, oculocutaneous albinism and Harlequin ichthyosis in which the severity of the clinical phenotype appears to justify PND in families at risk. More recently, preimplantation diagnoses of inherited diseases have become possible using in vitro fertilization techniques. The diagnosis consists of a blastomere biopsy of the six to ten-cell embryo and a DNA analysis of single blastomeres. Disease-free embryos are selected for transfer to the uterus, thereby avoiding the need for termination of a fetus found to be affected by conventional PND. Furthermore, carrying out a PND using a single fetal cell from the maternal blood, such as nucleated erythrocytes, has become technically feasible. Although there are many questions that remain unanswered, the outlook for further development of noninvasive PND in the future appears optimistic.

DNA-based prenatal diagnosis of generalized recessive dystrophic epidermolysis bullosa in six pregnancies at risk for recurrence

Linkage analyses in generalized recessive dystrophic epidermolysis bullosa (RDEB) have implicated the type VII collagen gene (COL7A1), which encodes the major component of anchoring fibrils, and recent identification of COL7A1 mutations has provided direct evidence for COL7A1 defects underlying RDEB. In this study, COL7A1 gene analysis was used to successfully perform first-trimester prenatal diagnosis in six families at risk for recurrence of the disease. In four families, three affected with the most severe variant of RDEB (the Hallopeau-Siemens form, HS-RDEB) and one with generalized nonmutilating RDEB, prenatal diagnosis was established by linkage analysis using polymerase chain reaction-based detection of PvuII and AluI intragenic restriction fragment length polymorphism. In two other HS-RDEB families, prenatal diagnosis was carried out by direct detection of mutations in COL7A1, using denaturing gradient gel electrophoresis analysis of polymerase chain reaction-amplified genomic fragments. Analysis of fetal DNA from chorionic villus biopsy or from amniotic fluid cells showed that the fetus had inherited at least one normal COL7A1 allele in all cases. Therefore, the fetus was predicted to be unaffected in the six pregnancies, and this has been confirmed in the newborn infants. Genotype analysis with COL7A1 polymorphic markers, or direct COL7A1 mutation detection in families at risk for the disease, represent early and rapid diagnostic alternatives to second-trimester evaluation of fetal skin samples, and thus offer a major advance in prenatal diagnosis of this life-threatening form of epidermolysis bullosa.

Analysis of skin-derived amniotic fluid cells in the second trimester; detection of severe genodermatoses expressed in the fetal period

Amniotic fluid contains skin-derived cells. To determine whether populations of amniotic fluid cells reflect genetic conditions, we surveyed the population of amniotic fluid cells from 36 fetuses at 16-21 weeks estimated gestational age at risk for junctional epidermolysis bullosa, recessive dystrophic epidermolysis bullosa, epidermolysis bullosa Dowling-Meara, harlequin ichthyosis, lamellar ichthyosis (nonbullous congenital ichthyosiform erythroderma), or Sjögren-Larson syndrome. Periderm cells, keratinocytes, cells of unknown epithelial origin, fibroblasts, fibrin clots, and urinary cast-like materials were seen in the amniotic fluid from normal fetuses. A large number of small macrophages phagocytizing collagen fibers was found in the amniotic fluid from all recessive dystrophic epidermolysis bullosa, some junctional epidermolysis bullosa fetuses, and a single epidermolysis bullosa Dowling-Meara fetus. Immuno-gold electron microscopy with anti-lysozyme and anti-CD68 antibodies confirmed that the cells morphologically identified as macrophages were active macrophages containing many lysosomes. The percentage of macrophages/total amniotic fluid cells in amniotic fluid samples from the fetuses affected with recessive dystrophic epidermolysis bullosa was significantly increased (12.30 +/- 0.20%) compared with that in the amniotic fluid from normal fetuses (1.30 +/- 0.65%) (p < 0.001). In amniotic fluid samples from fetuses affected with harlequin ichthyosis and lamellar ichthyosis, clumps of keratinized cells that contained disease-specific abnormal granules and lipid droplets were observed. These results indicate that the morphologic analysis of amniotic fluid cells can provide important supportive information for the prenatal diagnosis of several severe genodermatoses.

Diagnosis and prenatal diagnosis of epidermolysis bullosa herpetiformis (Dowling-Meara) in a mother, two affected children, and an affected fetus

In utero skin biopsy was performed on a fetus at risk of an uncertain form of epidermolysis bullosa (EB). The mother had produced two affected offspring diagnosed variously as having junctional or dystrophic EB. The two offspring and the fetus were products of different fathers. The mother claimed to have no disease and on clinical examination was without blisters. Examination of the fetal skin biopsy by light and electron microscopy revealed separation of the epidermal sheet from the majority of the biopsy sample, although occasional remnants of basal cells remained associated with the basement membrane. Aggregations of keratin filaments were observed within basal cells of the detached epidermis and in the attached basal cell remnants. The diagnosis was thus suggested to be epidermolysis bullosa Dowling-Meara. Re-review of the clinical and laboratory data from the affected infants revealed a clinical and histological pattern consistent with this diagnosis. Further discussion with the mother revealed that her skin had blistered as a child and that she presently had hyperkeratotic palms and soles. This history is consistent with the autosomal dominantly inherited epidermolysis bullosa herpetiformis (Dowling-Meara). This is the first reported prenatal diagnosis of EB Dowling-Meara. The morphological criteria of intraepidermal blistering and clumped keratin filaments within basal and immediately suprabasal cells characteristic of an affected individual postnatally also identified an affected fetus. There is, however, insufficient experience to be certain that these findings will hold from region to region in the body or among all affected fetuses, and thus prenatal diagnosis on a morphological basis should still be made with caution.

Occurrence of hereditary bullous epidermolyses in Croatia

To determine the occurrence of hereditary bullous epidermolyses (EB) in Croatia, Yugoslavia, from 1960 to 1987, cases were gathered from the hospital files of dermatologic and pediatric clinics and departments throughout the area. The diagnosis of EB type was made on the basis of clinical features, patients' histories, and light microscopy and electron microscopy findings. Fifty families with 58 patients were registered; 44 patients were examined personally by one of the authors. The most frequent type of EB in Croatia was recessive dystrophic EB Hallopeau-Siemens, occurring in 35 of the 58 individuals. Regional accumulation of cases within the Varazdin area was noted (13 patients). Prevalence of EB in Croatia is 0.956 cases per 100,000 inhabitants. One case of recessive dystrophic EB Hallopeau-Siemens occurred in about every 52,000 live births.

Fetal skin biopsy in prenatal diagnosis of some genodermatoses

Various methods of obtaining fetal skin for prenatal diagnosis of certain autosomal-recessive congenital genodermatoses have been assessed. An attempt was made to obtain fetal skin by fetoscopy in 15 patients prior to pregnancy termination for a variety of medical reasons at 18-26 weeks. Specimens were obtained only in five cases (8 successful attempts out of 48). In twelve cases, of which five had a history of a child with junctional (Herlitz type) or dystrophic (Hallopeau-Siemens type) epidermolysis bullosa or non-bullous congenital ichthyosiform erythroderma at 16-25 weeks of pregnancy, fetal skin was obtained without fetoscopy under direct ultrasonic control. Specimens were obtained in all cases (33 successful attempts out of 39). In three cases, fetal pathology was diagnosed by the method of semi-thin and ultra-thin skin sections, and the respective pregnancies were terminated.

Epidermolysis bullosa

During the last 10 years, there has been considerable progress in the knowledge of epidermolysis bullosa, which has led to recognition of at least 18 different varieties. This review article attempts to classify these varieties and to emphasize the orodental findings in patients with epidermolysis bullosa.

Prenatal diagnosis of dominant and recessive dystrophic epidermolysis bullosa: application and limitations in the use of KF-1 and LH 7:2 monoclonal antibodies and immunofluorescence mapping technique

Prenatal diagnosis is now possible for junctional and recessive dystrophic forms of epidermolysis bullosa (EB); however, there is no similar published experience for dominant dystrophic EB, although data with KF-1 monoclonal antibody suggests that both forms of dystrophic EB can be identified at least postnatally with this unique probe. We now report our experience with light microscopy, electron microscopy, immunofluorescence mapping, and KF-1 and LH 7:2 monoclonal antibodies, in both a mother with dominant dystrophic EB and her fetus at risk, and in a fetus previously shown to be affected with recessive dystrophic EB. KF-1 and LH 7:2 antigens were absent in recessive dystrophic EB fetal skin, identical to findings observed postnatally. LH 7:2 was normally expressed in a mother with dominant dystrophic EB and in her fetus at risk for this disease. In contrast, while KF-1 antigen was abnormally expressed in the affected mother, it was normally expressed in only 1/7 fetal biopsies despite the fact that this fetus was shown by light and electron microscopy and immunofluorescence mapping to be unaffected with dominant dystrophic EB. We conclude that 1) transmission electron microscopy can be used to prenatally exclude the diagnosis of dominant dystrophic EB (Cockayne-Touraine variety), 2) immunofluorescence mapping is an accurate technique for prenatal as well as postnatal diagnosis of EB, and 3) KF-1 cannot by itself be used as an accurate probe for the prenatal diagnosis of dominant dystrophic EB, due to the apparent variability in the time for the normal expression of KF-1 in fetal skin during the second trimester.

The spectrum of renal involvement in epidermolysis bullosa dystrophica hereditaria: report of two cases

Epidermolysis bullosa dystrophica Hallopeau-Siemens (EBDH) is one of the most severe inherited epidermolyses, a group of mechanobullous dermatological disorders. We observed two patients presenting with a severely multilating type of EBDH who developed biopsy-proven renal disease, which substantially altered the evolution and pathogenesis of their disease. In a boy, chronic postinfectious glomerulonephritis developed, most probably due to recurring superinfections of bullous skin lesions. He also experienced acute oliguric renal failure due to severe diarrhea during exacerbation of EBDH. A female patient developed a nephrotic syndrome due to secondary amyloidosis. Hypoalbuminemia caused further fluid losses through bullous skin lesions, aggravating intravascular hypovolemia and leading to rapid renal failure secondary to bilateral renal vein thrombosis. The study shows that, although rare, renal complications may alter the natural course of EBDH.

Rapid prenatal diagnosis of epidermolysis bullosa letalis using GB3 monoclonal antibody

The prenatal diagnosis of epidermolysis bullosa letalis was made by demonstrating a marked reduction of normal immunofluorescence staining with the monoclonal antibody GB3 in a fetal skin biopsy obtained at 18 weeks' gestation. The diagnosis was confirmed by conventional electron microscopy using established techniques. The affected pregnancy continued to term and a baby was delivered who rapidly developed blistering affecting the buttocks, lower limbs and mouth. This technique is simpler and quicker than electron microscopy, yet appears to retain the same degree of accuracy.

Prenatal diagnosis of congenital non-bullous ichthyosiform erythroderma (lamellar ichthyosis)

We report the first positive prenatal diagnosis of congenital non-bullous ichthyosiform erythroderma or lamellar ichthyosis. Fetal skin samples were obtained by fetoscopy at 21 weeks' gestation and examined by light and electron microscopy. Light microscopy revealed a thickened interfollicular epidermis with multiple layers of flattened cells and excessive keratinization of the epidermal lining of the follicular infundibulum. Electron microscopy of the thickened epidermis revealed granular cells that contained larger-than-normal keratohyalin granules and multiple layers of parakeratotic cornified cells. Although there was regional variation in the degree of interfollicular keratinization, follicles from all regions showed greater and more complete keratinization, indicating that they express the abnormality early enough in development to permit prenatal diagnosis at about 20 weeks' gestation.

Antenatal diagnosis of recessive dystrophic epidermolysis bullosa: collagenase expression in cultured fibroblasts as a biochemical marker

We performed fetoscopy and skin biopsy on a 19-week fetus at risk for recessive dystrophic epidermolysis bullosa (RDEB). Ultrastructural analysis of the tissue revealed dermolytic blister formation in the skin characteristic of the disease. To develop a biochemical test for use in antenatal diagnosis of RDEB, we established skin fibroblast cultures from the 20-week aborted fetus. The collagenase production by fetal RDEB fibroblast cultures was greater than seen in normal fetal fibroblast cultures. The concentration in culture medium from fetal RDEB cultures was 5.42 +/- 0.74 micrograms/ml (mean +/- SE) compared with 2.24 +/- 1.11 micrograms/ml in normal adult control cultures and 2.05 +/- 0.61 micrograms/ml in cultures from patients with other genetic forms of epidermolysis bullosa (p less than 0.025). In contrast, the concentration of collagenase in the fetal RDEB culture medium was not different from that seen in cell cultures from known patients with RDEB (5.34 +/- 1.12 micrograms/ml). Collagenase activity of the fetal RDEB medium was also increased approximately 3.5-fold. These data indicate that enhanced expression of collagenase by fetal RDEB skin fibroblasts can serve as a biochemical adjunct, and possibly an alternative, to morphologic examination of tissue for antenatal diagnosis.

Rapid prenatal diagnosis and exclusion of epidermolysis bullosa using novel antibody probes

Prenatal diagnosis of recessive dystrophic epidermolysis bullosa was successfully achieved at 19 weeks' gestation by indirect immunofluorescence examination of a fetal skin biopsy sample using the monoclonal antibody LH 7:2. The abortus displayed marked blistering and the diagnosis was confirmed by transmission electron microscopy (TEM). In 3 further pregnancies at risk for lethal junctional epidermolysis bullosa the diagnosis was excluded using the polyclonal antibody AA3. In all these studies the results were available within 4 h of receiving the samples. These new techniques offer a quick and simple alternative to TEM for midtrimester prenatal diagnosis of 2 severe recessive forms of epidermolysis bullosa.

Hereditary epidermolysis bullosa

Hereditary epidermolysis bullosa (EB) is a group of disorders of skin characterized by formation of blisters following minor trauma. There are at least sixteen types of hereditary EB. These types are reviewed in this article. There are several classifications of hereditary EB, and they are discussed, as well as current ideas on pathogenesis. Last, the treatment of this often recalcitrant group of diseases is discussed.

Rapid processing of fetal skin for prenatal diagnosis by light and electron microscopy

A method has been developed for rapid processing of fetal skin for prenatal diagnosis of hereditary skin diseases by light and electron microscopy. Fixation, dehydration, embedding, and polymerisation can be achieved in about 5 h. The quality of tissue preservation compares favourably with that produced by slower conventional techniques. This procedure may provoke a wider interest in the potential use of fetal skin biopsy in prenatal diagnosis, especially if identification of structural abnormalities is a feasible alternative to more time consuming biochemical analysis.

Epidermolysis bullosa: a review

Epidermolysis bullosa is a group of inherited disorders characterized by blistering of the skin as a result of minor trauma. The disease can be divided into three anatomical categories: Epidermolytic, where blister cleavage occurs within the epidermis; Junctional, which has blister cleavage within the lamina lucida; and Dermolytic, where blister cleavage occurs below the basal lamina in the upper papillary dermis. Each of these three categories can be divided into several distinct entities based on clinical and histologic criteria. Basic biochemical studies have increased our understanding of several of these diseases, most notably recessive dystrophic epidermolysis bullosa. Although therapy for patients with EB is largely supportive, increased knowledge of the biochemistry of these disorders is making direct therapeutic interventions possible.

The biology of human fetal skin at ages related to prenatal diagnosis

It is the goal of the present article to review the state of knowledge of human skin development and to indicate some of the questions being approached in current studies of human fetal skin. Because of the breadth of the topic, the discussion will be limited to two ages during gestation that correspond to periods when samples of fetal skin or amniotic fluid cells (which in part are derived from the skin) are used to evaluate the condition of the fetus. These periods correspond to ages when amniocentesis (14-16 weeks) and fetoscopy accompanied by fetal skin biopsy (19-20 weeks) are performed.

Genetically induced abnormalities of epidermal differentiation and ultrastructure in ichthyoses and epidermolyses: pathogenesis, heterogeneity, fetal manifestation, and prenatal diagnosis

Comparative ultrastructural investigations on the pathomorphogenesis of inherited ichthyoses and epidermolyses have shown that such heterogeneous skin disorders may serve as model systems for genetic interactions with developmental processes, such as keratinization, or functional systems, such as dermal-epidermal junctional integrity. Most interesting from the morphologic point of view are dominantly inherited skin disorders in the ichthyosis and epidermolysis bullosa groups in which primary structural defects of structural proteins have been demonstrated that seem to be under the direct control of the mutant gene. Such structural abnormalities concern keratohyalin in autosomal-dominant ichthyosis vulgaris, the tonofilament system in hystrix-like ichthyoses, and the anchoring fibrils in dominant dystrophic epidermolyses. Taking bullous congenital ichthyosiform erythroderma (epidermolytic hyperkeratosis) as a central example, we discuss the stability of such structural defects, the heterogeneity in the ultrastructural abnormalities of clinically closely similar entities (ichthyosis hystrix Curth-Macklin, congenital reticulate ichthyosiform erythroderma), and, in the latter keratinization disorder, the presence of an unusual filament system of unknown biochemical composition in the abnormal keratinocytes. Expression of mutant genes during fetal life and fetal manifestation of such abnormalities are a precondition for the prenatal diagnosis of genetic skin disorders (bullous ichthyosiform erythroderma, epidermolysis bullosa dystrophica Hallopeau-Siemens, Herlitz syndrome). Finally, problems related to the differentiation of mutant keratinocytes and of amniotic fluid cells of fetuses at risk of genetic skin disorders under the in vitro conditions of primary cell cultures are briefly discussed.

Antenatal diagnosis of genodermatoses

The technics of fetoscopy and fetal skin biopsy have expanded our capabilities for antenatal diagnosis of certain hereditary skin disorders (genodermatoses). The fetus and placenta can be visualized directly and skin biopsy specimens can be obtained for light and electron microscopic studies, tissue culture, and biochemical analysis. These technics have been utilized successfully in the prenatal diagnosis or exclusion of epidermolysis bullosa, epidermolytic hyperkeratosis, and harlequin ichthyosis in fetuses known to be at risk for these disorders, and they offer tremendous potential for prenatal diagnosis in a variety of other genodermatoses. Studies of tissue obtained by this procedure will undoubtedly expand our knowledge of the morphogenesis and biochemistry of fetal skin and will provide needed baseline data for the further development of these technics.

Prenatal diagnosis of oculocutaneous albinism by electron microscopy of fetal skin

Oculocutaneous albinism was diagnosed prenatally by electron microscopic examination of fetal skin samples taken during fetoscopy at 20 weeks of gestation. Melanosome development in hair bulb melanocytes progressed no further than stage II, indicating a lack of melanin synthesis. In 4 age-matched control fetuses, numerous stage IV melanosomes, signifying active melanin synthesis, were identified. The diagnosis was confirmed after the pregnancy was terminated at 22 weeks. Examination of the fetal eye showed absence of pigment in the retinal epithelium and uvea at a stage when ocular melanogenesis would normally be active. This study shows that oculocutaneous albinism can be detected in the second trimester using similar techniques to those employed in the prenatal diagnosis of epidermolysis bullosa and ichthyosis.