- Email: [email protected]
The gene for incontinentia pigmenti is assigned to Xq28
GENOMICS
4.427-429
(1989)
SHORT COMMUNICATION The Gene for lncontinentia A. SEFIANI,*+~ L. ABEL,t
Pigmenti
Is Assigned
to Xq28
5. HEUERTZ,* D. SINNETT,* L. LAVERGNE,$ D. LABUDA,* AND M. C. HORS-CAYLA*
l lNsERM U-12, HGpital des Enfants.-Malades,
749 rue de S&es, 75743 Paris Cedex 15, France; ttNSERM U-155, ChSteau de Longchamp, Bois de Boulogne, 750 7 6 Paris, France; 4 H6pital Sainte Justine, Mont&l, Quebec, Canada, and §Laboratoire de G&$tique, Facult4 de Medecine et de Pharmacie, Rabat, Maroc Received
July 11, 1988;
revised
September
26, 1988
restriction enzymes and analyzed with six specific single-copy DNA probes as described in Table 1. Linkage analysis was conducted assuming X-linked dominant inheritance of IP with 95% penetrance in afl’ected allele carrier females (Prigent, 1984) and 100%
A linkage study of eight families with incontinentia pigmenti (IP) has been performed, and linkage to site DXSBZ has been established. We suggest that the IP locus lies in the Xq terminal region on the long arm of the X chromosome. o 1s~ AC~~~III~ precls,lnc.
Incontinentia pigmenti (IP, McKusick 30830), also known as Bloch-Sulzberger syndrome, is a rare genodermatosis. This disease is a multisystem syndrome accompanied by dermatologic and sometimes neurologic, ocular, dental, or skeletal defects. Around the time of birth, the infant manifests inflammatory erythematous and vesicular skin disorders that evolve into verrucous lesions after a few weeks. Later, these lesions are replaced by linear or blotchy patterns of pigmentary change. Although there are exceptional unexplained cases of affected boys, the most probable mode of inheritance seems to be sex-linked, dominant, and lethal in males (Lenz, 1961; Carney, 1976). A cytogenetic location of IP on Xpll has been proposed following observation of six females with IP carrying an X/autosome translocation (Gilgenkrantz et al., 1985; Hodgson et al., 1985; Kajii et al., 1985; Cannizzaro and Hecht, 1987; McKusick, 1986); in all but one case, the breakpoint on the X chromosome involved the Xpll region. We recently excluded a localization on most of the Xp and especially on the Xpll region (Sefiani et al., 1988). In the present paper we exclude several Xq regions and assign the gene responsible for the familial form of incontinentia pigmenti to Xq28. Families in which there were two or more females affected by IP were studied, thus excluding isolated cases possibly arising by new mutation. Eight families with IP were investigated (Fig. 1). The procedures for DNA extraction, restriction enzyme digestion, gel electrophoresis, Southern blotting, hybridization to radioactively labeled probes, and autoradiography have been previously described (Sefiani et al., 1988). DNA samples were digested with several
%& 21 21
%& 2 13
Family 4
Family 5
Family 7
.-
Family 8
FIG. 1. Pedigrees of families with hereditary incontinentia pigmenti and DXS52 marker (effected females are indicated by solid circles; U, unknown genotypes). In order to follow more easily the segregation of different alleles, they have been arbitrarily designated by arabic numerals in each family. 427
OSSS-7543/S9
$3.00
Copyright 0 1989 by Academic Press, Inc. All rights of reproduction in any form reserved.
428
SHORT
COMMUNICATION
TABLE
1
X-Chromosome Probe cpx73 pXPGK-PVRI ~19-2 pXG12 36B-2 st14-1 F814
0.9
Markers
Locus
Localization
Enzyme
DXS159 PGKl DXS3 DXS94 DXSlO DXS52 DXS52
q12-q13 ql3 q21.3-q22 @2 @6 q28
PstI PstI TaqI PstI TaqI Td BClI
penetrance in affected allele carrier males. The mutation rate was fixed at lo-’ according to Vogel and Rathenberg (1975). All calculations were performed using the MLink program (Lathrop et aZ., 1984). Confidence intervals for the recombination fraction were calculated as described by Conneally et al. (1965). Results are shown in Table 2. We studied eight families for a total of 59 members and 37 possibly informative meioses. We showed (Table 2) a linkage between IP and site DXS52. Electrophoresis patterns obtained with the probe F814 are shown in Fig. 2. The DXS52 site is multiallelic (Oberl8 et al., 1985; Heilig et al., 1988) and 29 of 37 meioses were informative. A maximal lod score of Z = 3.5 was obtained for a recombination fraction 13= 0.05 (90% confidence interval = 0.00-0.22). This result assigns the gene for the familial form of IP to the distal part of the X chromosome long arm. Moreover, we can exclude a close or medium linkage of the gene responsible for IP with the sites DXS159PGK-DXS3-DXS94, which are localized in the proximal part of Xq, and with the site DXSlO, which is localized in Xq26. Of interest is the observation that
Heterozygosity 0.44
Data
for Incontinentia Lod
P. A. G. P. R. J. J.
0.47 0.50 0.44 0.77 0.80
from
Ref.
(2)
L. Pearson M. Michelson A. Bruns Szabo Nussbaum L. Mandel L. Mandel
(11) (1) (7) (3)
W-9 (9)
there are X/autosome translocations associated with a phenotype of incontinentia pigmenti. For five of these, the X breakpoint is in Xpll; for two others (McKusick, 1986; S. Gilgenkrantz, to be published), the breakpoint is in Xq21. We have previously excluded a localization in Xpl 1 (Sefiani et al., 1988). In the present work we also exclude a localization in Xq21. Finally, the gene that segregates in a family is in a different part of the X chromosome. One simple hypothesis is that two other genes in Xpll and Xq21 could be responsible for the incontinentia pigmenti phenotype and that we do not observe families with either a gene located in Xpll or Xq21 or a translocation with a breakpoint in Xq28 because of the small number of sporadic and familial cases studied. However, we are not completely satisfied with this hypothesis and wonder whether the incontinentia pigmenti phenotype in cases with a translocation could be an indirect, unspecific, and problematic consequence of the translocation itself. Further work on the Xq28 region of the X chromosome in relation to IP is under study with additional pedigrees and probes.
TABLE Linkage
Obtained
2
Pigmenti
(2) scores at various
Disease
and Six Marker
recombination
fractions
Loci
(0)
Probe
Location
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
N
DXS159 PGKl DXS3 DXS94 DXSlO DXS52
q12-q13 q13 q21.3-q22 @2 @6 q28
-co -co -cc -Co
-1.740 -3.223 -3.047 -2.346 -2.982 3.583
-1.033 -2.105 -1.864 -1.291 -3.746 3.449
-0.653 -1.488 -1.210 -0.717 -2.491 3.124
-0.413 -1.076 -0.787 -0.363 -1.659 2.706
-0.254 -0.777 -0.498 -0.138 -1.073 2.234
-0.146 -0.548 -0.296 -0.061 -0.651 1.730
-0.074 -0.367 -0.157 0.069 -0.352 1.215
-0.029 -0.220 -0.067 0.089 -0.152 0.714
-0.005 -0.100 -0.0016 0.065 -0.032 0.279
10 8 13 15 20 29
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
s28
0.504
3.142
3.390
3.505
3.561
3.583
3.582
3.566
3.536
N = informative
meioses.
DXS52 Note.
oZ4
SHORT
COMMUNICATION
429
6. CONNEALLY, P. M., EDWARDS, J. H., KIDD, K. K., LALOUEL, J.-M., MORTON, N. E., OTT, J., AND WHITE, R. (1985). Report of the committee on methods of linkage analysis and reporting. Cytogenet.
FIG. 2. Southern blot of DNA samples from three incontinentia pigmenti families (families 4, 5, and 6). The samples were digested with Bcfl and electrophoresed on 0.9% agarose gels.
ACKNOWLEDGMENTS We are very grateful to J. L. Mandel and his group for very helpful advice. This work was partially supported by a grant from For& de Recherche en Sax& du Qu&ec and by a grant from Con&l Scientifique de la Faculti de M&lecine Necker-Enfants Malades. D. Labuda is a research fellow and D. Sinnet was the recipient of a studentship from the Medical Research Council of Canada.
REFERENCES 1. ALDRIDGE, J., KUNKEL, L., BRUNS, G., TANTRAVAHI, U., LALOND, M., BREWSTER, T., MOREAU, E., WILSON, M., BROMLEY, W., RODERICK, T., AND LA’rr, S. A. (1984). A strategy to reveal high-frequency RFLPs along the human X chromosome. Amer.
J. Hum.
Gene%. 36:
546-564.
2. ARVEILER, B., HOFKER, M. H., BERGEN, A. A. B., PEARSON, P., AND MANDEL, J. L. (1987). A P&I RFLP detected by probe cpX73 (DXS159) in Xqll-q22. Nucleic Acids Res. 15: 5903. 3. BOGGS, B., AND NUSSHBAUM, R. L. (1984). Two anonymous Xspecific human sequences detecting RFLPs in region Xq26qter. Somut. Cell Mol. Genet. 10,607-613. 4. CANNIZZARRO, L. A., AND HECHT, F. (1987). Gene for incontinentia pigmenti maps to band Xpll with an (X;lO)(pll;q22) translocation. Clin. Genet. 32: 66-69. 5. CARNEY, R. G. (1976). Incontinentia pigmenti: A world statistical analysis. Arch. Dermatol. 112: 535-542.
Cell Genet.
40: 356-359.
7. DAVATELIS, G., SINISCALCO, M., AND SZABO, P. (1987). An anonymous single copy X-chromosome clone DXS94 from Xqll-q21 identifies a common RFLP. Nucleic Acids Res. 16: 4694. 8. GILGENKRANTZ, S., TRIDON, P., PINEL-BRIQUEL, N., BEUREY, J., AND WEBER, M. (1985). Translocation (X,9)(pll;q34) in a girl with incontinentia pigmenti. Ann. Genet. 28: 90-92. 9. HEILIG, R., OBERLE, I., ARVEILER, B., HANAUER, A., VIDAUD, M., AND MANDEL, J. L. (1988). Improved DNA markers for efficient analysis of fragile X families. Amer. J. Med. Genet. 30: 543-550. 10. HODGSON,S. V., NEVILLE, B., FEAR, R. W. A. C., AND BOBROW, M. (1985). Two cases of X/autosome translocation in female with incontinentia pigmenti. Hum. Genet. 71: 231-234. 11. HUTZ, M. H., MICHELSON, A. M., ANTONARAKIS, S. E., ORKIN, S. H., AND KAZAZIAN, H. H., JR. (1984). Restriction site polymorphism in the phosphoglycerate kinase gene on the X chromosome. Hum. Genet. 68: 217-219. 12. KAJII, T., TSUKAHAF& M., FUKUSHIMA, Y., HATA, A., MATSUO, K., AND KUROKI, Y. (1985). Translocation (X,13)(p11.21;q21.3) in a girl with incontinentia pigmenti and bilateral retinoblastoma. Ann. Genet. 28: 219-223. 13. LATHROP, G. M., LALOUEL, J. M., JULIER, C., AND OTT, H. (1984). Strategies for multilocus linkage analysis in humans. Proc. Natl. Acad. Sci. USA 81:3443-3446. 14. LENZ, W. (1961). Zur Genetik der Incontinentia Pigmenti. Ann. Paediatr. (Easel) 196: 149-165. 15. MCKUSICK, V. A. (1986). “Mendelian Inheritance in Man: Catalogs of Autosomial Dominant, Autosomal Recessive and X Linked Phenotypes,” Johns Hopkins Univ. Press, Baltimore. 16. OBERLB, I., CAMERINO, G., HEILIG, R., GRUNEBAUM, L., CAZENAVE, J., CRAPANZANO,C., MANNUCCI, P., AND MANDEL, J. L. (1985). Genetic screening for hemophilia A with a polymorphic DNA probe. N. Engl. J. Med. 312: 682-686. 17. PFUGENT,F. (1984). Incontinentia pigmenti. In “Dermatologie,” 12470 AlO, Encycl. Med. Chir., Paris. 18. SEFIANI, A., SINNEW, D., ABEL, L., SZPIRO-TAPIA, S., HEUERTZ, S., CRAIG, I., FRASER, N., KRUSE, T. A., FRYDMAN, M., PETER, M. O., SCHMUTZ, J. L., GILGENKRANTZ, S., MITCHELL, G., FREZAL, J., MELANCON, S., LAVERGNE, L., LABUDA, D., AND HORS-CAYLA, M. C. (1988). Linkage studies don’t confirm the cytogenetic location of Incontinentia pigmenti on Xpll. Hum. Genet.
80:
282-286.
19. VOGEL, F., AND RATHENBERG, R. (1975). Spontaneous mutation in man. In (H. Harris and K. Hirschhom, Eda.), ‘Aduances in Human Genetics” Vol 5, pp. 232-233, 237-238 (223-305), Plenum, New York.
4.427-429
(1989)
SHORT COMMUNICATION The Gene for lncontinentia A. SEFIANI,*+~ L. ABEL,t
Pigmenti
Is Assigned
to Xq28
5. HEUERTZ,* D. SINNETT,* L. LAVERGNE,$ D. LABUDA,* AND M. C. HORS-CAYLA*
l lNsERM U-12, HGpital des Enfants.-Malades,
749 rue de S&es, 75743 Paris Cedex 15, France; ttNSERM U-155, ChSteau de Longchamp, Bois de Boulogne, 750 7 6 Paris, France; 4 H6pital Sainte Justine, Mont&l, Quebec, Canada, and §Laboratoire de G&$tique, Facult4 de Medecine et de Pharmacie, Rabat, Maroc Received
July 11, 1988;
revised
September
26, 1988
restriction enzymes and analyzed with six specific single-copy DNA probes as described in Table 1. Linkage analysis was conducted assuming X-linked dominant inheritance of IP with 95% penetrance in afl’ected allele carrier females (Prigent, 1984) and 100%
A linkage study of eight families with incontinentia pigmenti (IP) has been performed, and linkage to site DXSBZ has been established. We suggest that the IP locus lies in the Xq terminal region on the long arm of the X chromosome. o 1s~ AC~~~III~ precls,lnc.
Incontinentia pigmenti (IP, McKusick 30830), also known as Bloch-Sulzberger syndrome, is a rare genodermatosis. This disease is a multisystem syndrome accompanied by dermatologic and sometimes neurologic, ocular, dental, or skeletal defects. Around the time of birth, the infant manifests inflammatory erythematous and vesicular skin disorders that evolve into verrucous lesions after a few weeks. Later, these lesions are replaced by linear or blotchy patterns of pigmentary change. Although there are exceptional unexplained cases of affected boys, the most probable mode of inheritance seems to be sex-linked, dominant, and lethal in males (Lenz, 1961; Carney, 1976). A cytogenetic location of IP on Xpll has been proposed following observation of six females with IP carrying an X/autosome translocation (Gilgenkrantz et al., 1985; Hodgson et al., 1985; Kajii et al., 1985; Cannizzaro and Hecht, 1987; McKusick, 1986); in all but one case, the breakpoint on the X chromosome involved the Xpll region. We recently excluded a localization on most of the Xp and especially on the Xpll region (Sefiani et al., 1988). In the present paper we exclude several Xq regions and assign the gene responsible for the familial form of incontinentia pigmenti to Xq28. Families in which there were two or more females affected by IP were studied, thus excluding isolated cases possibly arising by new mutation. Eight families with IP were investigated (Fig. 1). The procedures for DNA extraction, restriction enzyme digestion, gel electrophoresis, Southern blotting, hybridization to radioactively labeled probes, and autoradiography have been previously described (Sefiani et al., 1988). DNA samples were digested with several
%& 21 21
%& 2 13
Family 4
Family 5
Family 7
.-
Family 8
FIG. 1. Pedigrees of families with hereditary incontinentia pigmenti and DXS52 marker (effected females are indicated by solid circles; U, unknown genotypes). In order to follow more easily the segregation of different alleles, they have been arbitrarily designated by arabic numerals in each family. 427
OSSS-7543/S9
$3.00
Copyright 0 1989 by Academic Press, Inc. All rights of reproduction in any form reserved.
428
SHORT
COMMUNICATION
TABLE
1
X-Chromosome Probe cpx73 pXPGK-PVRI ~19-2 pXG12 36B-2 st14-1 F814
0.9
Markers
Locus
Localization
Enzyme
DXS159 PGKl DXS3 DXS94 DXSlO DXS52 DXS52
q12-q13 ql3 q21.3-q22 @2 @6 q28
PstI PstI TaqI PstI TaqI Td BClI
penetrance in affected allele carrier males. The mutation rate was fixed at lo-’ according to Vogel and Rathenberg (1975). All calculations were performed using the MLink program (Lathrop et aZ., 1984). Confidence intervals for the recombination fraction were calculated as described by Conneally et al. (1965). Results are shown in Table 2. We studied eight families for a total of 59 members and 37 possibly informative meioses. We showed (Table 2) a linkage between IP and site DXS52. Electrophoresis patterns obtained with the probe F814 are shown in Fig. 2. The DXS52 site is multiallelic (Oberl8 et al., 1985; Heilig et al., 1988) and 29 of 37 meioses were informative. A maximal lod score of Z = 3.5 was obtained for a recombination fraction 13= 0.05 (90% confidence interval = 0.00-0.22). This result assigns the gene for the familial form of IP to the distal part of the X chromosome long arm. Moreover, we can exclude a close or medium linkage of the gene responsible for IP with the sites DXS159PGK-DXS3-DXS94, which are localized in the proximal part of Xq, and with the site DXSlO, which is localized in Xq26. Of interest is the observation that
Heterozygosity 0.44
Data
for Incontinentia Lod
P. A. G. P. R. J. J.
0.47 0.50 0.44 0.77 0.80
from
Ref.
(2)
L. Pearson M. Michelson A. Bruns Szabo Nussbaum L. Mandel L. Mandel
(11) (1) (7) (3)
W-9 (9)
there are X/autosome translocations associated with a phenotype of incontinentia pigmenti. For five of these, the X breakpoint is in Xpll; for two others (McKusick, 1986; S. Gilgenkrantz, to be published), the breakpoint is in Xq21. We have previously excluded a localization in Xpl 1 (Sefiani et al., 1988). In the present work we also exclude a localization in Xq21. Finally, the gene that segregates in a family is in a different part of the X chromosome. One simple hypothesis is that two other genes in Xpll and Xq21 could be responsible for the incontinentia pigmenti phenotype and that we do not observe families with either a gene located in Xpll or Xq21 or a translocation with a breakpoint in Xq28 because of the small number of sporadic and familial cases studied. However, we are not completely satisfied with this hypothesis and wonder whether the incontinentia pigmenti phenotype in cases with a translocation could be an indirect, unspecific, and problematic consequence of the translocation itself. Further work on the Xq28 region of the X chromosome in relation to IP is under study with additional pedigrees and probes.
TABLE Linkage
Obtained
2
Pigmenti
(2) scores at various
Disease
and Six Marker
recombination
fractions
Loci
(0)
Probe
Location
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
N
DXS159 PGKl DXS3 DXS94 DXSlO DXS52
q12-q13 q13 q21.3-q22 @2 @6 q28
-co -co -cc -Co
-1.740 -3.223 -3.047 -2.346 -2.982 3.583
-1.033 -2.105 -1.864 -1.291 -3.746 3.449
-0.653 -1.488 -1.210 -0.717 -2.491 3.124
-0.413 -1.076 -0.787 -0.363 -1.659 2.706
-0.254 -0.777 -0.498 -0.138 -1.073 2.234
-0.146 -0.548 -0.296 -0.061 -0.651 1.730
-0.074 -0.367 -0.157 0.069 -0.352 1.215
-0.029 -0.220 -0.067 0.089 -0.152 0.714
-0.005 -0.100 -0.0016 0.065 -0.032 0.279
10 8 13 15 20 29
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
s28
0.504
3.142
3.390
3.505
3.561
3.583
3.582
3.566
3.536
N = informative
meioses.
DXS52 Note.
oZ4
SHORT
COMMUNICATION
429
6. CONNEALLY, P. M., EDWARDS, J. H., KIDD, K. K., LALOUEL, J.-M., MORTON, N. E., OTT, J., AND WHITE, R. (1985). Report of the committee on methods of linkage analysis and reporting. Cytogenet.
FIG. 2. Southern blot of DNA samples from three incontinentia pigmenti families (families 4, 5, and 6). The samples were digested with Bcfl and electrophoresed on 0.9% agarose gels.
ACKNOWLEDGMENTS We are very grateful to J. L. Mandel and his group for very helpful advice. This work was partially supported by a grant from For& de Recherche en Sax& du Qu&ec and by a grant from Con&l Scientifique de la Faculti de M&lecine Necker-Enfants Malades. D. Labuda is a research fellow and D. Sinnet was the recipient of a studentship from the Medical Research Council of Canada.
REFERENCES 1. ALDRIDGE, J., KUNKEL, L., BRUNS, G., TANTRAVAHI, U., LALOND, M., BREWSTER, T., MOREAU, E., WILSON, M., BROMLEY, W., RODERICK, T., AND LA’rr, S. A. (1984). A strategy to reveal high-frequency RFLPs along the human X chromosome. Amer.
J. Hum.
Gene%. 36:
546-564.
2. ARVEILER, B., HOFKER, M. H., BERGEN, A. A. B., PEARSON, P., AND MANDEL, J. L. (1987). A P&I RFLP detected by probe cpX73 (DXS159) in Xqll-q22. Nucleic Acids Res. 15: 5903. 3. BOGGS, B., AND NUSSHBAUM, R. L. (1984). Two anonymous Xspecific human sequences detecting RFLPs in region Xq26qter. Somut. Cell Mol. Genet. 10,607-613. 4. CANNIZZARRO, L. A., AND HECHT, F. (1987). Gene for incontinentia pigmenti maps to band Xpll with an (X;lO)(pll;q22) translocation. Clin. Genet. 32: 66-69. 5. CARNEY, R. G. (1976). Incontinentia pigmenti: A world statistical analysis. Arch. Dermatol. 112: 535-542.
Cell Genet.
40: 356-359.
7. DAVATELIS, G., SINISCALCO, M., AND SZABO, P. (1987). An anonymous single copy X-chromosome clone DXS94 from Xqll-q21 identifies a common RFLP. Nucleic Acids Res. 16: 4694. 8. GILGENKRANTZ, S., TRIDON, P., PINEL-BRIQUEL, N., BEUREY, J., AND WEBER, M. (1985). Translocation (X,9)(pll;q34) in a girl with incontinentia pigmenti. Ann. Genet. 28: 90-92. 9. HEILIG, R., OBERLE, I., ARVEILER, B., HANAUER, A., VIDAUD, M., AND MANDEL, J. L. (1988). Improved DNA markers for efficient analysis of fragile X families. Amer. J. Med. Genet. 30: 543-550. 10. HODGSON,S. V., NEVILLE, B., FEAR, R. W. A. C., AND BOBROW, M. (1985). Two cases of X/autosome translocation in female with incontinentia pigmenti. Hum. Genet. 71: 231-234. 11. HUTZ, M. H., MICHELSON, A. M., ANTONARAKIS, S. E., ORKIN, S. H., AND KAZAZIAN, H. H., JR. (1984). Restriction site polymorphism in the phosphoglycerate kinase gene on the X chromosome. Hum. Genet. 68: 217-219. 12. KAJII, T., TSUKAHAF& M., FUKUSHIMA, Y., HATA, A., MATSUO, K., AND KUROKI, Y. (1985). Translocation (X,13)(p11.21;q21.3) in a girl with incontinentia pigmenti and bilateral retinoblastoma. Ann. Genet. 28: 219-223. 13. LATHROP, G. M., LALOUEL, J. M., JULIER, C., AND OTT, H. (1984). Strategies for multilocus linkage analysis in humans. Proc. Natl. Acad. Sci. USA 81:3443-3446. 14. LENZ, W. (1961). Zur Genetik der Incontinentia Pigmenti. Ann. Paediatr. (Easel) 196: 149-165. 15. MCKUSICK, V. A. (1986). “Mendelian Inheritance in Man: Catalogs of Autosomial Dominant, Autosomal Recessive and X Linked Phenotypes,” Johns Hopkins Univ. Press, Baltimore. 16. OBERLB, I., CAMERINO, G., HEILIG, R., GRUNEBAUM, L., CAZENAVE, J., CRAPANZANO,C., MANNUCCI, P., AND MANDEL, J. L. (1985). Genetic screening for hemophilia A with a polymorphic DNA probe. N. Engl. J. Med. 312: 682-686. 17. PFUGENT,F. (1984). Incontinentia pigmenti. In “Dermatologie,” 12470 AlO, Encycl. Med. Chir., Paris. 18. SEFIANI, A., SINNEW, D., ABEL, L., SZPIRO-TAPIA, S., HEUERTZ, S., CRAIG, I., FRASER, N., KRUSE, T. A., FRYDMAN, M., PETER, M. O., SCHMUTZ, J. L., GILGENKRANTZ, S., MITCHELL, G., FREZAL, J., MELANCON, S., LAVERGNE, L., LABUDA, D., AND HORS-CAYLA, M. C. (1988). Linkage studies don’t confirm the cytogenetic location of Incontinentia pigmenti on Xpll. Hum. Genet.
80:
282-286.
19. VOGEL, F., AND RATHENBERG, R. (1975). Spontaneous mutation in man. In (H. Harris and K. Hirschhom, Eda.), ‘Aduances in Human Genetics” Vol 5, pp. 232-233, 237-238 (223-305), Plenum, New York.