American Journal of Medical Genetics 42539-541 (1992)
Mapping the Gene for Juvenile Onset Neuronal Ceroid Lipofuscinosis to Chromosome 16 by Linkage Analysis R.M. Gardiner Department of Paediatrics, University College and Middlesen School of Medicine, Rayne Institute, London, England The ceroid-lipofuscinosesare a group of inherited neurodegenerative disorders characterised by the accumulation of autofluorescent lipopigment in neurones and other cell types. The underlying biochemical defect is unknown. Juvenile onset neuronal ceroidlipofuscinosis (Batten disease; SpielmeyerVogt disease) is an autosomal recessive trait. Linkage studies were undertaken to determine the location of the Batten disease (CLN3) mutation. Studies were carried out on 205 members of 42 families in which there were 76 affected individuals. Families originatedfrom 7 North European countries and Canada. Serum samplesfrom 23 families,including a total of 48 affected children, were tested for a set of “classical markers.” A positive lod score was found with the haptoglobin (Hp)system. The combined male and female maximum lod score was 3.00 at 8 = 0.00 and 8 = 0.26,respectively. This provided an indication of localisation to the long arm of chromosome 16. Linkage analysis was then carried out in 42 families using DNA markers for loci on human chromosome 16. The maximal lod score between Batten disease and the locus D16S148 calculated for combined sexes was 6.05. No recombinants were observed. Multilocus analysis using 5 loci indicated the most likely order to be HP-D16S151-D16S150-CLN3-D16S148D16S147. Work is in progress to refine the genetic and physical localisation of the Batten disease gene using additional markers in this region and a panel of somatic cell hybrids. Methods
Received for publication April 5,1991;revision received July 1, 1991. Address reprint requests to Professor R.M. Gardiner, Department of Paediatrics, University College and Middlesex School of Medicine, The Rayne Institute, 5 University Street, London, WClE 6JJ England.
0 1992 Wiley-Liss, Inc.
are now available which should allow the gene to be isolated and characterised.
KEY WORDS: Batten disease, neurodegenerative disease, linkage
INTRODUCTION The last decade has witnessed a revolution in the power of linkage analysis in man. The construction of a linkage map of the human genome based on DNA markers has provided a new approach to the investigation of inherited diseases known only by their phenotype. Not only can the disease locus be mapped, but methods are now available which allow the disease gene itself to be isolated and characterised. The spectacularly successful work on cystic fibrosis illustrates this strategy of so-called “reverse genetics.” Batten disease (neuronal ceroid lipofuscinosis, or NCL) has much in common with cystic fibrosis. Both are autosomal recessive disorders which have resisted decades of biochemical investigation. Clues have emerged concerning their biochemical basis, but the precise protein defect remains elusive. In each, the phenotype is devastating and ultimately fatal. With these considerations in mind, a project to map the locus for juvenile onset NCL was initiated in Oxford in spring 1987. The juvenile form was chosen to maximise the availability of families with more than one affected child and to minimise the chance of heterogeneity. The latter risk can never be eliminated. If a clinically homogeneous disease arises from mutations at more than one locus, linkage analysis can fail. The project went forward entirely as a result of the tremendous enthusiasm and with the cooperation of many physicians and the families under their care. It met with extraordinary good fortune. A linked marker was found amongst the first few tested-haptoglobin. As it happens, this is an “old-fashioned protein marker first mapped in 1970. The disease gene could have been localised at any time in the last 20 years.
510
Gardiner et al.
MATERIALS AND METHODS Patients and Families Blood samples were collected from 205 members of 42 families in which 76 individuals were affected. There were 3 affected sibs in 4 pedigrees, 2 affected in 26 pedigrees, and one affected in 12. The number of unaffected ranged from one to 5 and totalled 45. A diagnosis of juvenile onset NCL was made on standard clinical criteria [Santavuori, 19881. In all cases, confirmation was established on histological grounds. The families originated from Great Britain, Germany, Netherlands, Norway, Finland, Sweden, Denmark, and Canada.
Marker Qping Twenty-three families were tested for a set of classical markers, including HP, C3, C6, BF, TF, GC, PI, APOH, and AHSG [Eiberg et al., 19891. Genotyping for DNA markers was carried out by Southern hybridisation using standard methodology [Old, 19861. Members of these kindreds were typed with 5 DNA markers regionally mapped on chromosome 16 (Table I). These included loci detected by anonymous DNA probes for which the map order has just been established by multilocus analysis in multigenerational reference families [Julier et al., 19901. Linkage Analysis Analysis of HP data was carried out with LIPED [Ott, 19731. DNA marker data were analysed with the computer program ILINK [Lathrop et al., 19851to calculate the sex-specific lod scores. The haptoglobin polymorphism data detected by serum analysis was combined with the DNA data on additional families, as the same polymorphism is identified. A more precise estimate for the location of the CLN3 gene was obtained by applying the method of location scores [Lathrop et al., 19851. The programme was adapted to allow male and female recombination frac-
tions between the markers comprising the fixed map to be entered independently.
RESULTS Pairwise linkage results between CLNS and HP are shown in Table 11. (The marked difference in male and female recombination fractions reflects the high ratio of female to male recombination in this region of chromosome 16.) Negative lod scores were found with the remaining “classical markers” tested. Pairwise linkage results between CLNS and 5 marker loci on chromosome 16 are shown in Table 111. The most tightly linked locus was D16S148. No recombinations were observed between the disease and alleles at this locus. A map summarising location scores calculated for CLN3 at various positions using multipoint analysis and a fixed map of the 5 marker loci is shown in Figure 1. Results are plotted on both the male and female map in view of the considerable sex difference in recombination in this region. There is no male recombination between the markers which flank CLN3 on the female map, and this interval therefore disappears on the male map. The CLN3 locus has a maximal location score of 48 (lod score 10.4) in the interval between D16S148 and D16S150. DISCUSSION These results provide unequivocal evidence that the Batten’s disease gene is located on chromosome 16. It is known that the infantile form of NCL maps to chromosome 1 [Jokiaho et al., 19901,and work is in progress to map the late-infantile sub-type. Prenatal diagnosis by histological means has been described in this group ofdisorders [Macleod et al., 1985; Uvebrant et al., 1987; Rapola et al., 19881. The identification of closely linked DNA markers allows a new approach to prenatal and preclinical diagnosis in a proportion of families. The map location of the disease mutation provides a starting point for an attempt to isolate the gene using
TABLE 1. Polymorphic DNA Markers on Chromosome 16 Locus symbol D16S147 D16S148
D16S150
D 16s151 HP
Locus name
Regional assignment
Probe
Restriction enzyme
DNA segment, Single copy DNA segment Single copy
p13.2-q13
pCJ52.95
Taq 1
p13.2-ql3
pCJ52.95
Msp 1
DNA segment, Single copy DNA segment Single copy Haptoglobin
p13.2-q13
pCJ52.161
Taq 1
q21-q22
pCJ52.209
Msp 1
q22.1
HP 9
Bcl 1
Allele size (kb) 5 all 2.9-3.7 3.4 3.1 2.0, 1.4 2.0, 1.1 A: 6.26.8 B: 8.416.0, 2.4 A: 5.013.9 B: 3.713.6, 1.4 9.6111.3
Frequency
Reference Julier et al. [19901
0.4 0.77 0.10 0.09 0.74, 0.26 0.98, 0.02 0.01, 0.15 0.81, 0.03 0.52, 0.48
Julier et al. [19901
Julier et al. [19901 Julier et al. [19901 Raugei et al. [19901
TABLE 11. Linkaee to HaDtoelobin* ~~~~~
Loci CLN-3-HP
~~
Sex
Male Female
~~
Lod (z) scores at various recombination fractions (0) 0.00 0.01 0.05 0.10 0.20 0.30 2.88 2.81 2.52 2.14 1.40 0.71 - 2.30 - 0.46 0.12 0.36 0.25
* A positive score was obtained with the haptoglobin system, with Z
=
0.40 0.19 0.08
e
0.00 0.20
2 2.88 0.36
2.88 at 0 = 0.00in males and 2 = 0.36 at 8 = 0.26, respectively.
Mapping the NCL Gene to Chromosome
541
TABLE 111. Pairwise Linkage Results ~
Recombination fraction (€0
Maximum lod score Loci CLN3-Dl6S147 CLN3-Dl6S148 CLN3-Dl6S150 CLN3-Dl6S151 CLN3-HP
(sex-specific)
(Z)
Male
Female
4.17 6.05 2.72 2.62 2.92
0.074 0.001 0.001 0.001 0.001
0.176 0.001 0.243 0.378 0.285
n
5
-
40-
30-
8
20-
C
.-0 L
0 10;
-1
0 0 b-50-
5
10
15
40 -
n
c5
L
0
5:
20-
C
10-
0
-1
IE
0 0
(Z)
Recombination fraction (0)
3.83 6.05 1.70 0.69 1.89
0.126 0.001 0.116 0.194 0.123
REFERENCES
30-
F .-c 0
lod score
-
0)
5:
Maximum
analysis. I am very grateful to Dr. Leena Peltonen and Dr. Irman Jokiaho for advice. encouragement. and close collaboration. I am grateful to the National Fund for Research into Crippling Diseases, the E. P. Abraham Trust, and the Medical Research Fund of Oxford University for financia1 support. The study would not have been possible without the generous cooperation of the patients, their families, and collaborating physicians: E. Andermann, I. Bjerre, E. Gommers, N. Gyring, G. Hosking, A. Kohlschutter, M. Neilberg, R. Nystad, R. Robinson, T. Rosenberg, I. Rosenbloom, U. Sjaastad, R. Stephens, P. Uvebrant, J . Wilson, and I. Zweije-Hofman. Excellent technical assistance was provided by Marianne Solymar, Joanne Ewing, Andrew Sandford, Mary Deadman, and Britt Cervin. Note: Current data localises CLNB to 1 6 ~ 1 2 .
I c5
~~
Sex-averaged -
10
20 30 40 50 Genetic location (cM)
60
70
80
Fig. 1. Support for possible locations of the CLNB gene with respect to the linkage map offive marker loci: A, Haptoglobin; B, D16S151; C, D16S150; D, D16S148; E, D16S147. Haptoglobin (A) was arbitrarily placed a t 0.0.Map distance in centimorgans is calculated using Haldane’s formula as described in the documentation of LINKAGE from the previously estimated recombination frequencies [Julier et al., 19901.The location score 1(WD)was calculated as described [Lathrop et al., 19851. Results are plotted on the male map (a) and female map (b). Note that there is no interval between C and D on the male map.
strategies similar to those applied to cystic fibrosis [Romrnens et al., 19891. Isolation of the disease gene should provide new insights into the biochemical basis of this group of diseases and allow the development of rational strategies for interfering with the disease phenotype. ACKNOWLEDGMENTS Dr. S. Reeders provided advice and encouragement at the outset. Dr. H. Eiberg and Professor J. Mohr collaborated in typing the families with “classical” markers as described. Dr. Cecile Julier kindly provided the chromosome 16 DNA markers and assistance with linkage
Eiberg H, Gardiner RM, Mohr J (1989): Batten disease (SpielmeyerSjogren disease) and haptoglobins (HJP): indication of linkage and assignment to chromosome 16. Clin Genet 36:217-218. Gardiner RM, Sandford A, Deadman M, Poulton J , Cookson W, Reeders S, Jokiaho I, Peltonen L, Eiberg H, Julier C: Batten disease (Spielmeyer-Vogt Disease, Juvenile onset neuronal ceroid lipofuscinosis) gene (CLN3)maps to human chromosome 16. Genomics 8:387-390. Jokiaho I, Puhakka L, Santavuori P, Manninen T, Nyman K, Peltonen L (1990): Infantile neuronal ceroid lipofuscinosis is not an allelic form of Batten’s disease. Genomics (in press). Julier C, Nakamura Y, Lathrop M, OConnell P, Leppert M, Mohandas T, Lalouel J-M, White R (1990): A primary map of 24 loci on human chromosome 16. Genomics 6419-427. Lathrop GM, Lalouel J-M, Julier C, Ott J (1985):Multi-locus analysis in humans: detection of linkage and estimation of recombination. Am J Hum Genet 37:482-498. Macleod PM, Dolman CL, Nickel RE, Chang E, Nags, Zonana J, Slivey K (1985): Prenatal diagnosis of neuronal ceroid-lipofuscinoses. Am J Med Genet 22381-789. Old J M (1986): Fetal DNA analysis. In Davies KE (ed): “Human Genetic Diseases.” Oxford: IRL Press, pp P1-P19. Ott J (1973): A computer programme for linkage analysis in human pedigress. Am J Hum Genet 2457A. Rapola J , Santavuori P, Heiskala H (1988): Placental pathology and prenatal diagnosis of infantile type of neuronal ceroidlipofuscinosis. Am J Med Genet [Suppll 599-103. Fbmmens JM, Ianuzzi MC, Kerem B, Drumm ML, Melmer G, Dean M, Rozmahel R, Cole JL, Dennedy D, Hidaka N, Zsiga M,Buchwald M, Riordan JR, Tsui L-C, Collins FS (1989): Identification of the cystic fibrosis gene: chromosome walking andjumptin. Science 245:10581065. Santavuori P (1988): Neuronal ceroid-lipofuscinosis in childhood. Brain Dev 10:80-83. Uvebrant P, Conradi NG, Hokergard K-H, Wahlstrom J, Mellqvist L (1987): First trimester diagnosis of neuronal ceroid-lipofuscinosis in chorionic villi. Neuropediatrics 18:117.
Mapping the Gene for Juvenile Onset Neuronal Ceroid Lipofuscinosis to Chromosome 16 by Linkage Analysis R.M. Gardiner Department of Paediatrics, University College and Middlesen School of Medicine, Rayne Institute, London, England The ceroid-lipofuscinosesare a group of inherited neurodegenerative disorders characterised by the accumulation of autofluorescent lipopigment in neurones and other cell types. The underlying biochemical defect is unknown. Juvenile onset neuronal ceroidlipofuscinosis (Batten disease; SpielmeyerVogt disease) is an autosomal recessive trait. Linkage studies were undertaken to determine the location of the Batten disease (CLN3) mutation. Studies were carried out on 205 members of 42 families in which there were 76 affected individuals. Families originatedfrom 7 North European countries and Canada. Serum samplesfrom 23 families,including a total of 48 affected children, were tested for a set of “classical markers.” A positive lod score was found with the haptoglobin (Hp)system. The combined male and female maximum lod score was 3.00 at 8 = 0.00 and 8 = 0.26,respectively. This provided an indication of localisation to the long arm of chromosome 16. Linkage analysis was then carried out in 42 families using DNA markers for loci on human chromosome 16. The maximal lod score between Batten disease and the locus D16S148 calculated for combined sexes was 6.05. No recombinants were observed. Multilocus analysis using 5 loci indicated the most likely order to be HP-D16S151-D16S150-CLN3-D16S148D16S147. Work is in progress to refine the genetic and physical localisation of the Batten disease gene using additional markers in this region and a panel of somatic cell hybrids. Methods
Received for publication April 5,1991;revision received July 1, 1991. Address reprint requests to Professor R.M. Gardiner, Department of Paediatrics, University College and Middlesex School of Medicine, The Rayne Institute, 5 University Street, London, WClE 6JJ England.
0 1992 Wiley-Liss, Inc.
are now available which should allow the gene to be isolated and characterised.
KEY WORDS: Batten disease, neurodegenerative disease, linkage
INTRODUCTION The last decade has witnessed a revolution in the power of linkage analysis in man. The construction of a linkage map of the human genome based on DNA markers has provided a new approach to the investigation of inherited diseases known only by their phenotype. Not only can the disease locus be mapped, but methods are now available which allow the disease gene itself to be isolated and characterised. The spectacularly successful work on cystic fibrosis illustrates this strategy of so-called “reverse genetics.” Batten disease (neuronal ceroid lipofuscinosis, or NCL) has much in common with cystic fibrosis. Both are autosomal recessive disorders which have resisted decades of biochemical investigation. Clues have emerged concerning their biochemical basis, but the precise protein defect remains elusive. In each, the phenotype is devastating and ultimately fatal. With these considerations in mind, a project to map the locus for juvenile onset NCL was initiated in Oxford in spring 1987. The juvenile form was chosen to maximise the availability of families with more than one affected child and to minimise the chance of heterogeneity. The latter risk can never be eliminated. If a clinically homogeneous disease arises from mutations at more than one locus, linkage analysis can fail. The project went forward entirely as a result of the tremendous enthusiasm and with the cooperation of many physicians and the families under their care. It met with extraordinary good fortune. A linked marker was found amongst the first few tested-haptoglobin. As it happens, this is an “old-fashioned protein marker first mapped in 1970. The disease gene could have been localised at any time in the last 20 years.
510
Gardiner et al.
MATERIALS AND METHODS Patients and Families Blood samples were collected from 205 members of 42 families in which 76 individuals were affected. There were 3 affected sibs in 4 pedigrees, 2 affected in 26 pedigrees, and one affected in 12. The number of unaffected ranged from one to 5 and totalled 45. A diagnosis of juvenile onset NCL was made on standard clinical criteria [Santavuori, 19881. In all cases, confirmation was established on histological grounds. The families originated from Great Britain, Germany, Netherlands, Norway, Finland, Sweden, Denmark, and Canada.
Marker Qping Twenty-three families were tested for a set of classical markers, including HP, C3, C6, BF, TF, GC, PI, APOH, and AHSG [Eiberg et al., 19891. Genotyping for DNA markers was carried out by Southern hybridisation using standard methodology [Old, 19861. Members of these kindreds were typed with 5 DNA markers regionally mapped on chromosome 16 (Table I). These included loci detected by anonymous DNA probes for which the map order has just been established by multilocus analysis in multigenerational reference families [Julier et al., 19901. Linkage Analysis Analysis of HP data was carried out with LIPED [Ott, 19731. DNA marker data were analysed with the computer program ILINK [Lathrop et al., 19851to calculate the sex-specific lod scores. The haptoglobin polymorphism data detected by serum analysis was combined with the DNA data on additional families, as the same polymorphism is identified. A more precise estimate for the location of the CLN3 gene was obtained by applying the method of location scores [Lathrop et al., 19851. The programme was adapted to allow male and female recombination frac-
tions between the markers comprising the fixed map to be entered independently.
RESULTS Pairwise linkage results between CLNS and HP are shown in Table 11. (The marked difference in male and female recombination fractions reflects the high ratio of female to male recombination in this region of chromosome 16.) Negative lod scores were found with the remaining “classical markers” tested. Pairwise linkage results between CLNS and 5 marker loci on chromosome 16 are shown in Table 111. The most tightly linked locus was D16S148. No recombinations were observed between the disease and alleles at this locus. A map summarising location scores calculated for CLN3 at various positions using multipoint analysis and a fixed map of the 5 marker loci is shown in Figure 1. Results are plotted on both the male and female map in view of the considerable sex difference in recombination in this region. There is no male recombination between the markers which flank CLN3 on the female map, and this interval therefore disappears on the male map. The CLN3 locus has a maximal location score of 48 (lod score 10.4) in the interval between D16S148 and D16S150. DISCUSSION These results provide unequivocal evidence that the Batten’s disease gene is located on chromosome 16. It is known that the infantile form of NCL maps to chromosome 1 [Jokiaho et al., 19901,and work is in progress to map the late-infantile sub-type. Prenatal diagnosis by histological means has been described in this group ofdisorders [Macleod et al., 1985; Uvebrant et al., 1987; Rapola et al., 19881. The identification of closely linked DNA markers allows a new approach to prenatal and preclinical diagnosis in a proportion of families. The map location of the disease mutation provides a starting point for an attempt to isolate the gene using
TABLE 1. Polymorphic DNA Markers on Chromosome 16 Locus symbol D16S147 D16S148
D16S150
D 16s151 HP
Locus name
Regional assignment
Probe
Restriction enzyme
DNA segment, Single copy DNA segment Single copy
p13.2-q13
pCJ52.95
Taq 1
p13.2-ql3
pCJ52.95
Msp 1
DNA segment, Single copy DNA segment Single copy Haptoglobin
p13.2-q13
pCJ52.161
Taq 1
q21-q22
pCJ52.209
Msp 1
q22.1
HP 9
Bcl 1
Allele size (kb) 5 all 2.9-3.7 3.4 3.1 2.0, 1.4 2.0, 1.1 A: 6.26.8 B: 8.416.0, 2.4 A: 5.013.9 B: 3.713.6, 1.4 9.6111.3
Frequency
Reference Julier et al. [19901
0.4 0.77 0.10 0.09 0.74, 0.26 0.98, 0.02 0.01, 0.15 0.81, 0.03 0.52, 0.48
Julier et al. [19901
Julier et al. [19901 Julier et al. [19901 Raugei et al. [19901
TABLE 11. Linkaee to HaDtoelobin* ~~~~~
Loci CLN-3-HP
~~
Sex
Male Female
~~
Lod (z) scores at various recombination fractions (0) 0.00 0.01 0.05 0.10 0.20 0.30 2.88 2.81 2.52 2.14 1.40 0.71 - 2.30 - 0.46 0.12 0.36 0.25
* A positive score was obtained with the haptoglobin system, with Z
=
0.40 0.19 0.08
e
0.00 0.20
2 2.88 0.36
2.88 at 0 = 0.00in males and 2 = 0.36 at 8 = 0.26, respectively.
Mapping the NCL Gene to Chromosome
541
TABLE 111. Pairwise Linkage Results ~
Recombination fraction (€0
Maximum lod score Loci CLN3-Dl6S147 CLN3-Dl6S148 CLN3-Dl6S150 CLN3-Dl6S151 CLN3-HP
(sex-specific)
(Z)
Male
Female
4.17 6.05 2.72 2.62 2.92
0.074 0.001 0.001 0.001 0.001
0.176 0.001 0.243 0.378 0.285
n
5
-
40-
30-
8
20-
C
.-0 L
0 10;
-1
0 0 b-50-
5
10
15
40 -
n
c5
L
0
5:
20-
C
10-
0
-1
IE
0 0
(Z)
Recombination fraction (0)
3.83 6.05 1.70 0.69 1.89
0.126 0.001 0.116 0.194 0.123
REFERENCES
30-
F .-c 0
lod score
-
0)
5:
Maximum
analysis. I am very grateful to Dr. Leena Peltonen and Dr. Irman Jokiaho for advice. encouragement. and close collaboration. I am grateful to the National Fund for Research into Crippling Diseases, the E. P. Abraham Trust, and the Medical Research Fund of Oxford University for financia1 support. The study would not have been possible without the generous cooperation of the patients, their families, and collaborating physicians: E. Andermann, I. Bjerre, E. Gommers, N. Gyring, G. Hosking, A. Kohlschutter, M. Neilberg, R. Nystad, R. Robinson, T. Rosenberg, I. Rosenbloom, U. Sjaastad, R. Stephens, P. Uvebrant, J . Wilson, and I. Zweije-Hofman. Excellent technical assistance was provided by Marianne Solymar, Joanne Ewing, Andrew Sandford, Mary Deadman, and Britt Cervin. Note: Current data localises CLNB to 1 6 ~ 1 2 .
I c5
~~
Sex-averaged -
10
20 30 40 50 Genetic location (cM)
60
70
80
Fig. 1. Support for possible locations of the CLNB gene with respect to the linkage map offive marker loci: A, Haptoglobin; B, D16S151; C, D16S150; D, D16S148; E, D16S147. Haptoglobin (A) was arbitrarily placed a t 0.0.Map distance in centimorgans is calculated using Haldane’s formula as described in the documentation of LINKAGE from the previously estimated recombination frequencies [Julier et al., 19901.The location score 1(WD)was calculated as described [Lathrop et al., 19851. Results are plotted on the male map (a) and female map (b). Note that there is no interval between C and D on the male map.
strategies similar to those applied to cystic fibrosis [Romrnens et al., 19891. Isolation of the disease gene should provide new insights into the biochemical basis of this group of diseases and allow the development of rational strategies for interfering with the disease phenotype. ACKNOWLEDGMENTS Dr. S. Reeders provided advice and encouragement at the outset. Dr. H. Eiberg and Professor J. Mohr collaborated in typing the families with “classical” markers as described. Dr. Cecile Julier kindly provided the chromosome 16 DNA markers and assistance with linkage
Eiberg H, Gardiner RM, Mohr J (1989): Batten disease (SpielmeyerSjogren disease) and haptoglobins (HJP): indication of linkage and assignment to chromosome 16. Clin Genet 36:217-218. Gardiner RM, Sandford A, Deadman M, Poulton J , Cookson W, Reeders S, Jokiaho I, Peltonen L, Eiberg H, Julier C: Batten disease (Spielmeyer-Vogt Disease, Juvenile onset neuronal ceroid lipofuscinosis) gene (CLN3)maps to human chromosome 16. Genomics 8:387-390. Jokiaho I, Puhakka L, Santavuori P, Manninen T, Nyman K, Peltonen L (1990): Infantile neuronal ceroid lipofuscinosis is not an allelic form of Batten’s disease. Genomics (in press). Julier C, Nakamura Y, Lathrop M, OConnell P, Leppert M, Mohandas T, Lalouel J-M, White R (1990): A primary map of 24 loci on human chromosome 16. Genomics 6419-427. Lathrop GM, Lalouel J-M, Julier C, Ott J (1985):Multi-locus analysis in humans: detection of linkage and estimation of recombination. Am J Hum Genet 37:482-498. Macleod PM, Dolman CL, Nickel RE, Chang E, Nags, Zonana J, Slivey K (1985): Prenatal diagnosis of neuronal ceroid-lipofuscinoses. Am J Med Genet 22381-789. Old J M (1986): Fetal DNA analysis. In Davies KE (ed): “Human Genetic Diseases.” Oxford: IRL Press, pp P1-P19. Ott J (1973): A computer programme for linkage analysis in human pedigress. Am J Hum Genet 2457A. Rapola J , Santavuori P, Heiskala H (1988): Placental pathology and prenatal diagnosis of infantile type of neuronal ceroidlipofuscinosis. Am J Med Genet [Suppll 599-103. Fbmmens JM, Ianuzzi MC, Kerem B, Drumm ML, Melmer G, Dean M, Rozmahel R, Cole JL, Dennedy D, Hidaka N, Zsiga M,Buchwald M, Riordan JR, Tsui L-C, Collins FS (1989): Identification of the cystic fibrosis gene: chromosome walking andjumptin. Science 245:10581065. Santavuori P (1988): Neuronal ceroid-lipofuscinosis in childhood. Brain Dev 10:80-83. Uvebrant P, Conradi NG, Hokergard K-H, Wahlstrom J, Mellqvist L (1987): First trimester diagnosis of neuronal ceroid-lipofuscinosis in chorionic villi. Neuropediatrics 18:117.
