Chromosome telomere integrity of human solid neoplasms

Eukaryotic chromosomes contain specialized structures at the termini called telomeres. This region of DNA is required for replication and stability of the chromosome. Telomere reduction can contribute to genetic instability and has been described in certain malignancies (e.g., colon, leukemia, giant cell tumor of bone). To determine whether telomere reduction is a generalized phenomenon in malignancies, the telomere integrity of genomic DNA isolated from tumor cells was determined from 39 individuals with 15 different malignancies categorized as musculoskeletal, epithelial, cranial, or other, and peripheral blood leukocytes from the same patient, when possible, or age-matched controls. Significant telomere reduction occurred randomly across histopathologic groups including giant cell tumor of bone, glioblastoma, colon cancer, and Wilms' tumor while telomere elongation occurred in chordoma. The other remaining 10 malignancies do not show significant differences in telomere lengths compared with controls.

Molecular genetic analysis of mentally retarded males with features of the fragile-X syndrome

The fragile-X[fra(X)] or Martin-Bell syndrome is the most common familial cause of mental retardation and is characterized by the presence of an Xq27.3 chromosome fragile site. Unstable DNA sequences representing large increases in the number of CGG trinucleotide DNA base repeats of the FMR-1 gene are located at the fragile site and responsible for the fra(X) syndrome. In order to identify whether cytogenetically normal yet mentally retarded males without a known cause of their retardation had expansion of the CGG repeat segment of the FMR-I gene, molecular genetic studies using Southern hybridization were performed with two DNA probes (fxa241 and Ox1.9) following digestion of genomic DNA from each patient with restriction enzymes Pstl and EcoRl/Eagl, respectively. DNA studies were performed on 20 (12.3%) out of 162 (122 white and 40 black people) cytogenetically normal mentally retarded males without a known cause of their retardation, but with high anthropometric discriminant values and/or clinical checklist scores identified previously and consistent with the fra(X) syndrome. None of the 20 males showed expansion of the CGG repeat of the FMR-1 gene detectable with the two probes used in this study. While heterogeneous single base pair substitutions, or small deletions or insertions in the FMR-I gene could exist in our patients, aberrations in other X-linked mental retardation genes, not identified to date but whose gene product can produce a phenotype similar to fra(X), either independently or in conjunction with the recently identified FMR-I protein, should be considered and are under investigation. Our study supports the idea that major FMR-I gene expansion detectable with Southern hybridization is rare in cytogenetically normal mentally retarded males, including those with physical and behavioural features seen in the fra(X) syndrome.

Use of fluorescence in situ hybridization (FISH) in the diagnosis of DiGeorge sequence and related diseases

The proximal portion of human chromosome 22q has been implicated in the pathogenesis of a clinically diverse group of conditions including DiGeorge sequence (DGS), velocardiofacial syndrome, and CHARGE association as well as isolated conotruncal heart anomalies. Frequently, overlap in the clinical presentation of these syndromes occurs and, recently, the presence of microdeletions on chromosome 22q11.2 with varying frequencies has been demonstrated in these syndromes. Using fluorescence in situ hybridization (FISH), we assessed 20 consecutive patients who were cytogenetically and clinically evaluated for a suspected syndrome that could be due to a microdeletion of chromosome 22q11.2. After cytogenetic testing and full clinical evaluation, we compared the results by FISH with the final clinical diagnosis and karyotype results. We found that microdeletions of 22q11.2 were detected in three of the five patients who were evaluated for DGS. The three cases with microdeletions appeared clinically to have DGS while the two negative cases were more atypical. High-resolution banding techniques did not detect a microdeletion in any of the cases; however, one of the 20 patients had a translocation between chromosomes 13 and 22. This patient also had a microdeletion of 22q11.2 detected by FISH and clinical features of DGS. None of the patients who were evaluated for disorders related to DGS showed microdeletions. We conclude that FISH is a useful, easily applied technique for the diagnosis of 22q11.2 microdeletion syndromes, particularly DGS. This test may also be useful in genetic counseling and in both prenatal and postnatal diagnoses.

Cytogenetic, telomere, and telomerase studies in five surgically managed lumbosacral chordomas

Lumbosacral chordomas are rare skeletal sarcomas of the spine that originate from the remnant notochord. The understanding of this human cancer is limited to observations of its clinical behavior and its embryonic link. Thus, we performed chromosome and molecular analyses from five surgically harvested chordomas in an effort to document genetic and biochemical abnormalities which might aid in understanding the tumor biology of this understudied neoplasm. Cytogenetic analysis of the five chordomas revealed normal results in four patients and random abnormalities in only one tumor cell in the 100 cells studied from the fifth patient. A repeat telomeric probe (TTAGGG)50 was hybridized to genomic DNA isolated from chordoma cells (and HeLa cells) and digested with HinfI. The tumor DNA was paired with leukocyte DNA from age-matched controls and revealed telomere elongation in four of the four chordoma patients studied with molecular genetic techniques. Conversely, telomere length reduction has been reported during in vitro senescence of human fibroblasts, giant cell tumor of bone, colon cancer, intracranial tumors, childhood leukemia, Wilms tumor, and in HeLa cells. Telomerase activity (telomerase is required to maintain telomere integrity) was also determined by visualizing the extension of radioactive telomeric repeats on DNA sequencing gels. The telomeric fragments were assembled during incubation of the cytoplasmic extract containing telomerase. Telomerase activity was observed in HeLa (positive control and commercially available cell line), giant cell tumor of bone (positive control tumor cells from living patients), and in chordoma cells from one of the two chordoma patients (but to a lesser degree compared with HeLa). As expected, the chordoma patients' fibroblasts exhibited no telomerase activity.

Photoanthropometric study of craniofacial traits of individuals with Prader-Willi syndrome

A photoanthropometric method, which enables an objective description of facial structures, was used to better delineate the craniofacial characteristics of 37 individuals with Prader-Willi syndrome (PWS; 21 males and 16 females; 22 with 15q11q13 deletions and 15 with normal-appearing chromosome 15s) between the ages of 0 to 12 years. Facial parameters were measured from strict frontal and profile photographic 35 mm slides and compared with other facial measurements from the same face (e.g., palpebral fissure width to bizygomatic diameter). We studied 16 photoanthropometric craniofacial indices following the protocols established by Stengel-Rutkowski et al. [1984: Hum Genet 67:272-295] and Butler et al. [1988: Am J Med Genet 30:165-168]. Based on our measurements of 37 Prader-Willi syndrome individuals, none of the parameters were consistently outside of the normal range when compared with photoanthropometric index standards for age established from white control children [Stengel-Rutkowski et al., 1984]. However, several suggestive findings were documented by our analysis including: narrow palpebral fissure width [particularly in older children (6-12 years)], high midface, broad interalar distance, short back of the nose, prominent high chin, and broad low-set ears. No significant differences were found in craniofacial parameters between deletion or nondeletion Prader-Willi syndrome patients with this methodology. These craniofacial parameters (many not previously evaluated in PWS patients) may become useful for early detection, and aid in the diagnosis and the study of the development of the characteristic face seen in Prader-Willi patients.

Meniscal ossicle: radiographic and MR imaging findings

PURPOSE

To determine the magnetic resonance (MR) imaging appearance of meniscal ossicles and correlate that with the radiographic and clinical features.

MATERIALS AND METHODS

Radiographs and MR images were studied retrospectively in six patients with meniscal ossicles; all patients had intermittent discomfort in the knee, and five patients had experienced knee trauma. Imaging findings were correlated with the clinical history. Four patients underwent arthroscopy.

RESULTS

All patients had a visible ossicle on conventional radiographs initially interpreted as a loose joint body. MR imaging features included a corticated marrow-containing structure within the substance of the medial meniscus near the tibial attachment that appeared as a rounded focus of increased signal intensity on T1-weighted images that decreased in signal intensity on T2-weighted images.

CONCLUSION

Meniscal ossicles have a characteristic MR appearance that may help distinguish them from loose bodies. They should be considered diagnostically when a circumscribed ossification is identified near the posterior horn of the medial meniscus on radiographs.

Genetic anticipation and abnormal gender ratio at birth in familial primary pulmonary hypertension

The genetic basis of familial primary pulmonary hypertension (FPPH) is unknown, but the clinical and pathologic features are the same as in sporadically occurring primary pulmonary hypertension (PPH). Because few families with this disease have been reported, the mode of inheritance and genetic features have not been clearly established. We previously reported a tendency for decreasing age of onset in subsequent generations of affected families. The purpose of this study was to examine the pattern of inheritance in a large number of families in an attempt to find clues to pathogenesis. From 24 families we studied 429 members, 124 of whom were known to carry the gene for disease. We constructed cumulative mortality curves for each gender of the 99 affected individuals. We analyzed gender ratios of progeny of affected members and carriers and compared age at death of affected members by generation. More females (160) than males (122) were born to persons carrying the gene, p < 0.01, suggesting selective wastage of male fetuses or an abnormal primary sex ratio. Genetic anticipation was confirmed; the age at death was 45.6 +/- 14.5 versus 36.3 +/- 12.6 versus 24.2 +/- 11 standard deviation (SD) years in successive generations, p < 0.05. Five cases of male-to-male transmission were observed, excluding X-linkage. Age at death was the same for males and females. More females had the gene (84 females, 40 males) and more females with the gene developed disease (72 of 84 females [86%] versus 27 of 40 males [68%]). The disease has highly variable penetrance among families.(ABSTRACT TRUNCATED AT 250 WORDS)

Telomerase activity and oncogenesis in giant cell tumor of bone

BACKGROUND

Benign giant cell tumor of bone (GCT) is a primary skeletal neoplasm with an unpredictable pattern of biologic aggressiveness and cytogenetic findings characterized by telomeric associations and telomeric reduction. The role of maintaining telomeric integrity is performed by telomerase. To determine if telomerase activity is present, cell extracts from fibroblasts and tumor cells from five patients with GCT were analyzed and compared with HeLa (a positive control cell line).

METHODS

Telomerase activity was detected by visualizing the extension of radioactive telomeric repeats on DNA sequencing gels. Telomere reduction was assessed using southern blot analyses of the restriction enzyme Hinf I digested DNA with a radio-labeled telomere probe.

RESULTS

Telomerase or telomerase-like activity was detected in the cell extracts from HeLa and tumor cells. However, GCT telomerase activity varied and was less than that observed in HeLa, but no activity was detected from fibroblasts. In addition, telomere reduction was seen in DNA isolated from both HeLa and GCT but not in fibroblasts or age-matched controls.

CONCLUSION

Telomere reduction and telomerase activity may be oncogenic sustaining events required to maintain the transformed phenotype seen in GCT.

Blood specimens from patients referred for cytogenetic analysis: Vanderbilt University experience from 1985 to 1992

Cytogenetic records were examined from consecutive nononcology blood specimens from 2,821 patients referred for cytogenetic services to Vanderbilt University Medical Center, Nashville, Tenn, from January 1985 to December 1992. We grouped the records according to reasons for referral and diagnoses. The most common reasons for referral were history of multiple abortions/miscarriages (23.3%), possibility of chromosomal abnormality (18.8%), and possible presence of the fragile X syndrome (15.6%). Overall, 2,418 (85.7%) patients were found to have normal chromosomes, and 403 (14.3%) patients were diagnosed with a cytogenetic abnormality. For example, 20 (5.4%) of the 373 males referred for the fragile X syndrome, or 1.4% of all males (20 of 1,428) excluding those with ambiguous genitalia, were diagnosed with this syndrome while 8 (2.1%) of the 373 males had a chromosome abnormality other than the fragile X chromosome. In addition, 85 (70.2%) of 121 males referred for Down syndrome had this syndrome, and only 53 (40.8%) of 130 females referred for Down syndrome had this diagnosis. This study should assist physicians in middle Tennessee and surrounding areas by increasing their awareness of the types and frequencies of cytogenetic diseases and by providing figures for comparison with other regions of the country.

Antley-Bixler syndrome: report of a patient and review of literature

We report a patient with Antley-Bixler syndrome and review 13 patients from the literature. The cardinal features of this condition include craniosynostosis, severe mid-face hypoplasia, proptosis, choanal atresia/stenosis, frontal bossing, dysplastic ears, depressed nasal bridge, radiohumeral synostosis, long-bone fractures and femoral bowing, urogenital abnormalities and a normal karyotype. Early death was identified in 54% of the reported cases, usually due to respiratory complications. The oldest patient at the time of follow up was 10 years of age. Intellectual performance has been variable (developmental testing of our patient at 30 months of age showed a range of developmental skills equivalent to 6 to 11 months of age). Chronic respiratory distress, especially if accompanied by periods of apnea, may be important in the causation of mental retardation. Some patients with the syndrome have normal intelligence, which suggests a normally developing brain, particularly if a craniectomy is performed to treat sutural synostosis and indicates that there may be secondary factors (e.g., apnea) playing a role in the mental retardation (as seen in our patient with a history of apnea) in patients with the Antley-Bixler syndrome. Since choanal atresia/stenosis which diminishes the airway passage is a cardinal feature of this syndrome, choanal stenting should be performed on those patients with this finding during infancy to decrease the airway obstruction. All patients followed beyond infancy were ambulatory, including our patient at 35 months of age, who will take steps with assistance. Although most cases are sporadic, there were reports of recurrence in siblings of both sexes in two families, suggesting an autosomal recessive mode of inheritance.

Dosage and allelic restriction fragment studies and PCR analysis of the H-ras locus in giant cell tumor of bone

Several studies have shown that giant cell tumor of bone frequently exhibits telomeric associations, commonly at chromosome 11p, which is also the location of the H-ras oncogene. In addition, rare H-ras alleles are more common among cancer patients than among healthy controls and point mutations of this oncogene have also been reported in several malignancies. These data led us to investigate gene dosage, restriction fragment-length size, and point mutations for H-ras in giant cell tumor of bone. Quantitative Southern blot analysis revealed no amplification of the H-ras oncogene in tumor DNA compared with DNA from peripheral blood in the same patient or from control subjects. In addition, no point mutations were detected in codons 12, 13, or 61 (mutations of these codons have been reported in other neoplasms) of the H-ras gene. No differences were noted in restriction fragment-length polymorphisms between tumor and peripheral blood in the same patient and no loss of heterozygosity was detected. In addition, there was no increased frequency of rare H-ras alleles (8% of alleles) in giant cell tumor patients compared to controls (21% of alleles) in our study. However, large allele sizes (> 8.5 kb) were significantly overrepresented in GCT patients compared with healthy controls. In our study, three of 12 alleles were found to be rare in the healthy controls but were common among GCT patients. Our data suggest that the H-ras oncogene is unlikely to be the site of a biologically significant primary lesion in GCT tumorigenesis.

Telomere reduction in giant cell tumor of bone and with aging

Giant cell tumor of bone is a benign, primary skeletal neoplasm that has an unpredictable pattern of biologic aggressiveness, and cytogenetically demonstrates genetic instability by exhibiting telomeric associations. Molecular analysis of telomeres from giant cell tumor of bone demonstrated reduction of telomere length (average loss of 500 base pairs) in eight individuals when compared with their leukocyte DNA. Those tumors which exhibited telomeric associations were found to have a greater reduction in telomere length than tumors not exhibiting them. For comparison, eleven cytogenetically healthy control individuals (7 females and 4 males, age range 2 weeks to 70 years) were included in this study. They demonstrated loss of telomere size (average 40 base pairs per year) with advancing age and the greatest rate of telomere reduction was identified in the young. Thus, the functional consequences of telomere shortening in a neoplastic cell may prove fundamental to sustaining the transformed phenotype in giant cell tumor of bone.

Metacarpophalangeal pattern profile analysis in Brachmann-de Lange syndrome

We analyzed the metacarpophalangeal pattern profile (MCPP) of 19 individuals with Brachmann-de Lange syndrome (BDLS) and calculated a mean syndrome profile. Fourteen of 19 individuals with BDLS had significant positive correlations which indicated clinical homogeneity. Discriminant analysis of individuals with BDLS compared with a sample of normal individuals produced a correct classification rate of 100% based on a function of 2 MCPP variables that may provide a useful tool for assisting in the diagnosis of BDLS. An average pattern variability index calculated for the BDLS patients was 1.9 indicating an abnormal hand pattern in this syndrome.

Metacarpophalangeal pattern profile analysis in Williams syndrome

Many patients with Williams syndrome (WS) are not diagnosed until they are old enough to demonstrate the characteristic personality and facial changes. A number of these changes are quite subtle and none of them is present in all affected individuals. The cause of WS remains obscure and consequently, there are no cytogenetic, biochemical, or molecular studies to help in the diagnosis of patients in whom the diagnosis is uncertain. We have generated a mean WS metacarpophalangeal pattern profile (MCPP) on 21 clinically diagnosed individuals with WS. This mean syndrome profile shows that WS hands are smaller than average age-matched control hands and that the distal phalanx of the thumb is disproportionately large with respect to the rest of the hand. A mathematical model, which effectively discriminates WS patients from unaffected control individuals, was developed using discriminant analysis of the MCPP data. Of the 21 WS patients classified by this method, only 2 were misclassified as "normal." Similarly, 2 of the 24 control individuals were misclassified as "WS," yielding an over-all successful classification rate of 91%.

Clinical and molecular studies in fragile X patients with a Prader-Willi-like phenotype

A special subphenotype of the fragile X syndrome is reported which is characterised by extreme obesity with a full, round face, small, broad hands/feet, and regional skin hyperpigmentation. It resembles the Prader-Willi syndrome (PWS) and might therefore be named 'Prader-Willi-like'. Unlike the PWS, these PW-like fragile X patients lack the neonatal hypotonia with feeding problems during infancy followed by hyperphagia from toddlerhood. We describe five new fragile X patients and present a clinical update of three previously described patients with the PW-like phenotype. In one family, segregation of either the classical Martin-Bell or the PW-like phenotype was observed and in another family there was repeated transmission of the PW-like phenotype. Previously, one of the patients had been misdiagnosed as having classical PWS, based on clinical findings. Molecular studies of the FMR-1 gene showed the typical full mutations as seen in fragile X syndrome males. Molecular analysis of the 15q11-13 region, which is deleted in the majority of classical PWS patients, did not show any detectable abnormalities. In a group of 26 patients with suspected Prader-Willi syndrome but without detectable molecular abnormalities of chromosome 15, one fragile X patient was found. These clinical and molecular findings illustrate the necessity to perform DNA analysis of the FMR-1 gene in mentally retarded patients presenting with a PW phenotype but without the PWS specific cytogenetic/molecular abnormalities of chromosome 15.

Anthropometric and craniofacial patterns in mentally retarded males with emphasis on the fragile X syndrome

Anthropometric and craniofacial profile patterns indicating the percent difference from the overall mean were developed on 34 physical parameters with 31 white, mentally retarded males (23 adults and 8 children) with the fra(X) syndrome matched for age with 31 white, mentally retarded males without a known cause of their retardation. The fra(X) syndrome males consistently showed larger dimensions for all anthropometric variables, with significant differences for height, sitting height, arm span, hand length, middle finger length, hand breadth, foot length, foot breadth, and testicular volume. A craniofacial pattern did emerge between the two groups of mentally retarded males, but with overlap of several variables. Significant differences were noted for head circumference, head breadth, lower face height, bizygomatic diameter, inner canthal distance, ear length and ear width, with the fra(X) syndrome males having larger head dimensions (head circumference, head breadth, head length, face height and lower face height), but smaller measurements for minimal frontal diameter, bizygomatic diameter, bigonial diameter, and inner canthal distance. Several significant correlations were found with the variables for both mentally retarded males with and without the fra(X) syndrome. In a combined anthropometric and craniofacial profile of 19 variables comparing 26 white fra(X) syndrome males (13 with high expression (> 30%) and 13 with low expression (< 30%), but matched for age), a relatively flat profile was observed with no significant differences for any of the variables. Generally, fra(X) syndrome males with increased fragile X chromosome expression have larger amplifications of the CGG trinucleotide repeat of the FMR-1 gene. No physical differences were detectable in our study between fra(X) males with high expression and apparently larger amplifications of the CGG trinucleotide repeats compared with those patients with low expression. Our research illustrates the use of anthropometry in identifying differences between mentally retarded males with or without the fra(X) syndrome and offers a comprehensive approach for screening males for the fra(X) syndrome and selecting those individuals for cytogenetic and/or molecular genetic testing.

Clinical and cytogenetic survey of institutionalized mentally retarded patients with emphasis on the fragile-X syndrome

A detailed clinical and cytogenetic survey for the fragile-X syndrome was undertaken on 201 institutionalized mentally retarded males with no previously recognized cause of retardation, and the causes of mental retardation were summarized from a total of 595 institutionalized male and female patients after the review of their medical records including clinical and cytogenetic data. Among the 201 males clinically and cytogenetically examined, five (2.5%) had abnormal chromosome findings with four (2%) having the fragile-X syndrome. Twelve of the males (6.0%) were diagnosed with a single gene disorder. In the present study, mental retardation was classified as possibly due to multifactorial causes when a genetic syndrome, chromosome abnormality or environmental insult was not identified, but mental retardation was present in one or more first and/or second degree relatives, but did not follow a recognizable inheritance pattern. Hence, mental retardation was recorded in other family members and may indicate possible multifactorial causes in 45 males (22.4%). An environmental insult was noted in 25 males (12.4%); unexplained birth defects in three males (1.5%); a specific condition or diagnosis identified, but cause unknown (e.g. Rubinstein-Taybi syndrome) in 10 males (5%); and no diagnosis made in the remaining 101 males (50.2%). Of all 595 patients (334 males and 261 females), including the 201 males who had undergone a detailed clinical and cytogenetic evaluation, 39 (6.6%) had abnormal chromosome findings, with Down's syndrome noted in 31 of the patients. Twenty-five patients (4.2%) were diagnosed with a single gene disorder while mental retardation was noted in other family members and may indicate possible multifactorial causes in 64 patients (10.8%). An environmental insult was noted in 170 patients (28.6%); unexplained birth defects in 17 patients (2.9%); a specific condition or diagnosis but cause unknown in 27 patients (4.5%); and no diagnosis made in 253 patients (42.5%). Clinical and cytogenetic screening of mentally retarded patients for the fragile-X syndrome and other causes of mental retardation is helpful in identifying individuals and their families who may benefit from genetic services such as counseling and treatment. This study was performed over an approximate 2 year period from 1987 to 1989.

Molecular analysis of transforming growth factor beta in giant cell tumor of bone

Giant cell tumor of bone (GCT) is a primary bone neoplasm with unique cytogenetic findings including telomeric associations. Elevated expression of message RNA for transforming growth factor beta (TGF beta), but not transforming growth factor alpha (TGF alpha), has been reported in this tumor. Further investigation of GCT was undertaken to determine whether genetic loci for TGF beta in GCT patients with and without chromosome abnormalities are altered. Due to the reported TGF beta overexpression in GCT, qualitative and quantitative Southern blot analyses with TGF beta 1 and TGF beta 2 and an internal control probe (p3-21) were performed with tumor DNA and DNA from normal tissue on ten patients with GCT and control individuals. No obvious TGF beta 1 or TGF beta 2 gene alterations were detected. Normal copy numbers were calculated when comparing tumor and normal DNA from GCT patients as well as DNA from control individuals. Abnormal chromosome findings, including telomeric associations, marker chromosome, double minutes, chromosome fragments, ring chromosomes (possibly representing intra-chromosome telomeric associations), and polyploid cells were observed in seven of the ten patients with GCT. Chromosomes 11, 16, 19, 20, and 21 were most commonly observed in telomeric associations, with the terminus of the long arm of chromosome 19 being the most frequent. We conclude that there are no TGF beta 1 or TGF beta 2 gene alterations detected in GCT with the methodologies described, and that telomeric associations are a reproducible cytogenetic characteristic of this neoplasm.

The extracellular matrix of reparative tissue in the vitreous: fibronectin production in proliferative diabetic retinopathy membranes

In a preliminary investigation into the origins of the extracellular matrix glycoprotein fibronectin in proliferative diabetic retinopathy (PDR) membranes, four globes containing PDR membranes were subjected to in situ hybridisation and immunohistochemical studies. Fibronectin mRNA was found in PDR membrane cells in two of the four globes. The fibronectin-producing cells exhibited fibroblast-like or macrophage-like morphology. Occasional intraretinal macrophage-like cells which contained fibronectin mRNA were also observed in three of the eyes. Variable fibronectin immunoreactivity was observed in all the PDR membranes, while the fibronectin staining pattern in the underlying retina was similar to that reported for albumin in eyes with breakdown of the blood-retina barrier. The findings suggest that fibronectin in PDR membranes originates from both plasma-derived fibronectin and the membrane cells, and support the concept that extracellular matrix components play an important role in PDR membrane progression.

Prader-Willi syndrome: consensus diagnostic criteria

The diagnosis of Prader-Willi syndrome (PWS) is based on clinical findings that change with age. Hypotonia is prominent in infancy. Obesity, mild mental retardation or learning disability, and behavior problems, especially in association with food and eating, result in a debilitating physical and developmental disability in adolescence and adulthood. No consistent biological marker is yet available for PWS in spite of recent research activity in cytogenetics and molecular genetics. Diagnostic criteria for PWS were developed by consensus of seven clinicians experienced with the syndrome in consultation with national and international experts. Two scoring systems are provided: one for children aged 0 to 36 months and another one for children aged 3 years to adults. These criteria will aid in recognition of the syndrome in hypotonic infants and in obese, mildly retarded, behaviorally disturbed adolescents and adults. They will also ensure uniform diagnosis for future clinical and laboratory research in PWS.

Multiplex PCR of three dinucleotide repeats in the Prader-Willi/Angelman critical region (15q11-q13): molecular diagnosis and mechanism of uniparental disomy

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are distinct mental retardation disorders caused by a deficiency of paternal (PWS) or maternal (AS) contributions for chromosome 15 by either deletion or uniparental disomy (UPD). To further study the molecular mechanisms involved in these disorders and to improve molecular diagnostic methods, we have isolated three dinucleotide repeat markers in the PWS/AS critical region. An Alu-CA PCR method was used to isolate CA-repeat markers directly from yeast artificial chromosome (YAC) clones identified by probes IR4-3R (D15S11), LS6-1 (D15S113), and GABAA receptor B3 (GABRB3). Three markers with 6-11 alleles and 73-83% heterozygosities were identified and analyzed by multiplex PCR. Gene-centromere mapping was performed on a panel of ovarian teratomas of known meiotic origin, and showed the most proximal marker, IR4-3R, to be 13 cM (95% confidence limits: 7-19 cM) from the centromere of chromosome 15. Molecular diagnostic studies were performed on 20 PWS and 9 AS patients. In 17 patients with deletions, the parental origin of deletion was determined. Ten PWS patients were shown to have maternal heterodisomy. Since these markers are only 13 cM from the centromere, heterodisomy indicates that maternal meiosis I nondisjunction is involved in the origin of UPD. In contrast, two paternal disomy cases of AS showed isodisomy for all markers tested along the length of chromosome 15. This suggests a paternal meiosis II nondisjunction event (without crossing over) or, more likely, monosomic conception (due to maternal nondisjunction) followed by chromosome duplication.(ABSTRACT TRUNCATED AT 250 WORDS)

Genetic conditions among patients receiving genetic services in middle Tennessee

We reviewed genetics charts of 2235 patients seen from 1985 to 1990 at Vanderbilt University Medical Center, Nashville, Tennessee, and summarized the 20 most common reasons for referral (occurring in 1138 of the patients) and the diagnoses or conditions among patients receiving genetic services in one of four clinical settings (prenatal counseling clinics, general genetics clinics, outreach genetics clinics, and ward consultations). The five most common reasons for referral were advanced maternal age (> or = 35 years) (203/1138, or 18% of patients), followed by dysmorphic features/multiple congenital anomalies (MCA) (185/1138; 16%), developmental delay/mental retardation (MR) (168/1138; 15%), Down's syndrome (103/1138; 9%), and abnormal maternal serum alpha-fetoprotein (MSAFP) (74/1138; 7%). The five most common diagnoses or conditions identified for all genetics patients were advanced maternal age (> or = 35 years) (195/906; 22%), developmental delay/MR (111/906; 12%), dysmorphic features/MCA (107/906; 12%), Down's syndrome (88/906; 10%), and multiple fetal losses (57/906; 6%). Of the 20 most common diagnoses or conditions categorized in 602 of the 906 patients, a multifactorial cause was observed in 25% of those patients; a chromosomal cause was observed in 26% of cases of Down's syndrome, accounting for 55% of the chromosomal disorders; a single gene disorder was observed in 17% of patients; an environmental cause was seen in 4%; and an unknown cause was noted in 28%. We hope this study will help physicians in middle Tennessee and surrounding areas by increasing their awareness of the types and frequencies of genetic diseases so that misdiagnoses and delayed referrals can be avoided.

Keratan sulphate in rheumatoid arthritis, osteoarthritis, and inflammatory diseases

Serum concentrations of antigenic keratan sulphate determined by an enzyme linked immunosorbent assay (ELISA) with a monoclonal antibody were studied in patients with rheumatoid arthritis (RA), osteoarthritis, ankylosing spondylitis, other inflammatory diseases, and a large control group of women without arthritis. Mean keratan sulphate concentrations were low in 117 women with RA compared with 227 female control subjects matched for age drawn from a community survey. There were significant correlations between serum keratan sulphate concentrations in patients with RA and serum C reactive protein and the erythrocyte sedimentation rate. Serum keratan sulphate concentrations were also low in 29 men and women with ankylosing spondylitis and 29 patients with arthritis and high concentrations of C reactive protein. In 98 women undergoing an operation for benign breast disease there were decreases in serum keratan sulphate concentrations after the operation which correlated with doses in serum C reactive protein. No differences were found in keratan sulphate concentrations in 137 women with osteoarthritis compared with controls. Within the group with osteoarthritis there were no differences for the various joint groups and there was no obvious correlation with radiographic severity or progression. These findings suggest serum keratan sulphate is unlikely to be useful as a diagnostic marker in osteoarthritis or RA but indicate a role for inflammation in the regulation of cartilage loss.

Fibronectin synthesis in subretinal membranes of proliferative vitreoretinopathy

In situ hybridisation and immunohistochemical studies were conducted on six surgically excised subretinal membranes of proliferative vitreoretinopathy to investigate whether displacement of retinal pigment epithelial and glial cells to subretinal membranes was associated with fibronectin production by the subretinal membrane cells. Fibronectin messenger RNA (mRNA) and fibronectin immunoreactivity were observed in some cells in all of the subretinal membranes studied and up to 30% of the cells in individual specimens showed intense labelling for fibronectin mRNA. The results support the concept that the cells in subretinal membranes produce fibronectin. Locally produced fibronectin may play a role in subretinal membrane cohesion, and displacement of retinal pigment epithelial and glial cells from their normal location may induce the cells to manufacture fibronectin. Fibronectin production may be more prominent in migrating subretinal cells.

The frequency of uniparental disomy in Prader-Willi syndrome. Implications for molecular diagnosis

BACKGROUND

Prader-Willi syndrome is a genetic disorder characterized by infantile hypotonia, obesity, hypogonadism, and mental retardation, but it is difficult to diagnose clinically in infants and young children. In about two thirds of patients, a cytogenetically visible deletion can be detected in the paternally derived chromosome 15 (15q11q13). Recently, patients with Prader-Willi syndrome have been described who do not have the cytogenetic deletion but instead have two copies of the 15q11q13 region that are inherited from the mother (with none inherited from the father). This unusual form of inheritance is known as maternal uniparental disomy. Using molecular genetic techniques, we sought to determine the frequency of uniparental disomy in Prader-Willi syndrome.

METHODS

We performed molecular analyses using DNA markers within 15q11q13 and elsewhere on chromosome 15 in 30 patients with Prader-Willi syndrome who had no cytogenetically visible deletion. We also studied their parents. Three patients with Prader-Willi syndrome who had a cytogenetic deletion served as controls.

RESULTS

In 18 of the 30 patients without a cytogenetic deletion (60 percent), we demonstrated the presence of maternal uniparental disomy for chromosome 15 and its association with advanced maternal age. In another eight patients (27 percent), we identified large molecular deletions. The remaining four patients (13 percent) had evidence of normal biparental inheritance for chromosome 15; three of these patients were the only ones in the study who had some atypical clinical features.

CONCLUSIONS

In about 20 percent of all cases, Prader-Willi syndrome results from the inheritance of both copies of chromosome 15 from the mother (maternal uniparental disomy). With the combined use of cytogenetic and molecular techniques, the genetic basis of Prader-Willi syndrome can be identified in up to 95 percent of patients.

Localisation of fibronectin mRNA in the rheumatoid synovium by in situ hybridisation

The distribution of fibronectin, an extracellular matrix glycoprotein which plays a part in fibrosis and tissue repair, has previously been described using immunohistochemical methods. These do not differentiate between locally synthesised and plasma derived fibronectin. In this work the distribution of cells actively synthesising fibronectin was assessed by in situ hybridisation using a radiolabelled antisense RNA probe in synovial biopsy samples from patients with rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, and control subjects without inflammatory disease. Large amounts of fibronectin mRNA were found specifically in synovial lining cells, providing evidence for the local production of fibronectin in the synovium. Levels of fibronectin mRNA were variable between patients. These differences were not related to the diagnosis or to the subintimal inflammatory cell infiltrate; where there was synovial lining cell hyperplasia there was a concomitant increase in the number of cells containing fibronectin mRNA, which was consistent with increased levels of immunoreactive fibronectin at this site. Increased levels of fibronectin in synovial fluid in patients with rheumatoid arthritis may be due to an increased number of lining cells secreting the protein, rather than upregulation of the gene by these cells.

Standards for selected anthropometric measurements in males with the fragile X syndrome

Standards (95th, 50th, and 5th percentiles) in fragile X syndrome for weight, height, head circumference, ear length, and testicular volume are reported. For comparison with fragile X syndrome standardized curves, normal control data from the literature were similarly plotted and curves produced. These standards reflect the physical parameters that are frequently abnormal in males with the fragile X syndrome and should be useful in the medical management of patients with this syndrome. The standards may also be used to help identify those individuals, particularly the younger males, for chromosome studies to confirm the clinical impression of the fragile X syndrome.

Local production of fibronectin by ectopic human retinal cells

The distribution of fibronectin mRNA and fibronectin in adult human retina and epiretinal membranes was investigated by in situ hybridisation and immunohistochemical techniques. The cells in normal adult retina contained little or no fibronectin mRNA and the retina only showed fibronectin immunoreactivity in retinal vessels. The cells in detached neuroretina did not contain fibronectin message but the vitreoretinal interface of the detached retina exhibited variable fibronectin immunoreactivity. Retinal glia, retinal pigment epithelium and fibroblast-like cells in membranes at the vitreoretinal juncture (epiretinal membranes) showed variable labelling with the fibronectin mRNA probe and all the membranes immunostained for fibronectin. No difference could be detected between membrane cell types in the intensity of labelling with the mRNA probe or for fibronectin immunoreactivity. The results indicate that cells in situ in attached and detached adult human retina do not produce fibronectin. Although fibronectin at the vitreoretinal juncture in retinal detachment is probably partly derived from plasma fibronectin resulting from breakdown of the blood-retinal barrier, ectopic retinal cells produce fibronectin and contribute to the glycoprotein epiretinal membranes.

Cytogenetic abnormalities in a rare case of giant cell osteogenic sarcoma

The cytogenetic analysis of a rare, nonirradiated case of giant cell tumor of bone with osteogenic sarcoma transformation is presented for the first time in a 19-year-old female. Telomeric associations involving 4p, 8p, 11p, 14p, 17p, 17q, and 20q were observed. Additionally, monosomy 13, 11p abnormalities and marker chromosomes were identified in tumor cells. Chromosome 11 involvement, particularly 11p translocations and 11p telomeric associations, were frequently observed in the tumor cells obtained from our patient, which suggests that chromosome 11p may play a role in the development of giant cell osteogenic sarcoma.

Telomeric associations and consistent growth factor overexpression detected in giant cell tumor of bone

Tumor specimens from 15 patients with giant cell tumor (GCT) of bone were cytogenetically analyzed. A subset of five individuals had tumor cells harvested and polyadenylated RNA isolated. Multiple Northern blots were performed utilizing radiolabeled probes for the growth factors TGF beta 1, TGF beta 2, TGF beta 3, and TGF alpha (TGF, transforming growth factor). RNAs from other types of neoplasms and nonneoplastic cells were examined as controls. The most consistent cytogenetic abnormality detected involved multiple telomeric associations (TAs), most frequently involving the terminus of the long arm of chromosome 19 (19q). Northern blot analysis revealed a consistent expression of TGF beta 1 and TGF beta 2 with an inconsistent mRNA expression for the other TGFs. There was a relative overexpression of mRNA for TGF beta 2. The gene location for TGF beta 1 is near the 19q terminus and thus it is speculated that TGF beta may play a role in the neoplastic transformation of GCT.

Standards for selected anthropometric measurements in Prader-Willi syndrome

We report standards (95th, 50th, and 5th centiles) in Prader-Willi syndrome for weight, height, sitting height, head circumference, head length, head breadth, hand length, middle finger length, palm length, hand breadth, foot length, foot breadth, triceps skinfold, and subscapular skinfold. For comparison with Prader-Willi syndrome standardized curves, normal control data from the literature were plotted similarly and standard curves were produced. We encourage the use of these standards with the examination of patients who have Prader-Willi syndrome and in the comparison of the patient who has Prader-Willi syndrome with other similarly affected individuals. The standards may also be useful for assisting in the diagnosis of Prader-Willi syndrome, particularly in younger individuals.

Hereditary lymphedema and distichiasis

Two patients with lymphedema-distichiasis syndrome illustrate that both Milroy's disease and late-onset hereditary lymphedema are sometimes associated with distichiasis. It is important for ophthalmologists to be aware of the lymphedema-distichiasis syndrome because of its ophthalmic manifestations and the associated systemic abnormalities that can be potentially life threatening.

A 15-item checklist for screening mentally retarded males for the fragile X syndrome

A 15-item checklist, including physical and behavioral features frequently observed in fragile X syndrome, was used in a prospective study of 188 mentally retarded males in order to identify males at risk for this syndrome. Of the 188 males, 19 were found to have the fragile X syndrome, while the remaining 169 males had no recognizable cause of their mental retardation, including normal chromosomes. Significant differences (p less than 0.01) were found between mentally retarded males with and without the fragile X syndrome with increased hyperactivity; shorter attention span; more tactile defensiveness, hand-flapping, perseverative speech, and hyperextensibility; large ears and testes; higher frequency of simian creases or Sydney lines and plantar creases; and more positive family histories of mental retardation in the fragile X syndrome males. Multiple regression and discriminant analyses of the 188 males indicated several physical features were useful predictors for inclusion in the fragile X syndrome group. An overall correct classification rate of 93% was achieved based on 6 variables (plantar crease, simian crease, hyperflexibility, large testes, large ears, and a positive family history of mental retardation) that were entered into the discriminant equation. Therefore, our experience with a 15-item checklist suggests the potential of screening for the fragile X syndrome in mentally retarded males and that 6 of the 15 variables were particularly good predictors of this syndrome.

Anthropometric comparison of mentally retarded males with and without the fragile X syndrome

An anthropometric survey of 41 variables (weight, height, 10 linear, 4 breadth, 22 craniofacial, 2 skinfold, and testicular volume), including multivariate discriminant analysis, was undertaken on 110 mentally retarded males (39 with and 71 without the fra(X) syndrome). The mean Z scores of the fra(X) syndrome males fell between -2.00 and 8.38 for bizygomatic diameter and testicular volume, respectively, and the range of the mean Z scores of the non-fra(X) males was from -2.64 to 2.26 for hand breadth and testicular volume, respectively. There was a statistically significant difference (P less than .05) between fra(X) and non-fra(X) males for 18 measurements (weight, height, 7 linear, 2 breadth, 5 craniofacial, 1 skinfold, and testicular volume), with the greater measurements (excluding bizygomatic diameter) found in fra(X) males. Sitting height, knee-buttock length, middle finger length, and hand length were negatively correlated (P less than .05) with age, whereas bizygomatic diameter, ear length, and ear width were positively correlated (P less than .05) with age and head circumference, head length, and outer canthal distance were positively correlated (P less than .05) with fra(X) chromosome expression in the fra(X) males. Triceps and subscapular skinfold thicknesses were negatively correlated (P less than .05) with age, whereas ankle breadth, ear length, ear width, and nose length were positively correlated (P less than .05) in the non-fra(X) males. Discriminant analysis of 34 fra(X) and 71 non-fra(X) males resulted in a discriminant function based on 6 of 17 anthropometric variables and age.(ABSTRACT TRUNCATED AT 250 WORDS)

Reliability of ultrasound in the prenatal diagnosis of urinary tract abnormalities

To investigate the ability of ultrasonography to detect urinary tract abnormalities prenatally, we reviewed the records of 26 pregnancies diagnosed by prenatal ultrasound to have urinary tract anomalies. We compared the prenatal diagnoses with postnatal renal and urinary tract pathology. This comparison showed different degrees of agreement for different prenatal diagnoses (2 individuals had more than one diagnosis): 4 of 8 for multicystic kidneys, 1 of 1 for polycystic kidney disease, 1 of 2 for renal agenesis, 6 of 7 for ureteropelvic junction obstruction, 1 of 3 for posterior urethral valves, 4 of 5 for no pathology noted, and 2 of 2 for other abnormalities. Prenatal diagnosis and postnatal findings were in agreement in 68% of cases. Varying levels of diagnostic reliability should be considered when managing pregnancies complicated by fetal urinary tract abnormalities and subsequent postnatal evaluation and diagnosis. Further efforts are needed to improve on the techniques and reliability of prenatal diagnosis of urinary tract abnormalities.

An infant with deletion of the distal long arm of chromosome 15 (q26.1----qter) and loss of insulin-like growth factor 1 receptor gene

We report on an infant with a previously undescribed chromosome 15 deletion (q26.1----qter) and compare the clinical findings with those of 7 reported patients with deletions of distal 15q, as well as ring chromosome 15 syndrome patients. Most of the patients with deletions of distal 15q, including our patient, have intrauterine growth retardation (IUGR), microcephaly, abnormal face and ears, micrognathia, highly arched palate, renal abnormalities, lung hypoplasia, failure to thrive, and developmental delay/mental retardation. Several genes have been assigned to the 15q25----qter region, including insulin-like growth factor 1 receptor (IGF1R). DNA analysis from our patient documented the loss of one IGF1R gene copy. Our study further localizes the IGF1R gene distal to the 15q26.1 band. It is interesting to speculate that the severe IUGR and postnatal growth deficiency of our patient and other patients with similar chromosome 15 deletions are related to the loss of an IGF1R gene copy which may lead to an abnormal number and/or structure of the receptors.

Antibodies to cardiolipin and intermediate filaments: a study of autoimmunity in rheumatoid arthritis

Autoantibodies to cardiolipin and intermediate filaments have both been reported with increased frequency in rheumatoid arthritis. We evaluated the frequency, pathological significance, and diagnostic relevance of these autoantibodies in a series of 124 patients and controls. We studied 81 patients with rheumatoid arthritis, 23 with osteoarthritis, and 20 normals. Antibodies to cardiolipin were measured by an ELISA method and antibodies to intermediate filaments were measured by indirect immunofluorescence using HEp2 cells. Antibodies to cardiolipin were present in 58% of rheumatoid patients and antibodies to intermediate filaments were present in 55% rheumatoid patients. They were both predominantly of IgM class, and were more frequent than in normal or osteoarthritic controls. Correlating levels of both these autoantibodies to clinical and laboratory measures of disease activity such as Ritchie articular index and C-reactive protein level showed that no consistent relationships existed. They were not related to other auto-antibodies such as rheumatoid factors and anti-nuclear antibodies, nor to each other. These results show that antibodies to cardiolipin and intermediate filaments in rheumatoid arthritis are of no diagnostic value, they are not related to disease activity, and have no relationship to other autoimmune disturbances. We suggest that several pathological mechanisms must be involved in the development of autoantibodies in rheumatoid arthritis.

Chromosome lesions which could be interpreted as "fragile sites" on the distal end of Xq

Chromosome lesions which could be interpreted as "fragile sites" on the distal end of the long arm of the X chromosome were identified during a cytogenetic study of 160 mentally retarded adult males with no apparent cause of their mental retardation and one normal adult female with a family history of fra (X) syndrome. Peripheral blood samples were cultured in either M199 or RPMI 1640 medium with FUdR or BrdU. Metaphases were examined for chromosome lesions or fragile sites on the distal end of Xq and 3 distinct sites were observed: Xq26, Xq27.2, and Xq27.3. Other chromosome lesions at Xq28 were observed and interpreted as nonspecific telomeric structural changes. Chromosome lesions were observed in cells from 14 of the 161 individuals. These included: 5 patients with an Xq26 site, 2 with the recently reported Xq27.2 site, 4 with the Xq27.3 site (characteristic of the fra (X) syndrome), 2 with nonspecific telomeric structural changes, and one individual with 2 lesions (a nonspecific telomeric structural change and an Xq26 site). Additional research is necessary to determine the frequency and clinical significance, if any, of lesions occurring in this region of the X chromosome and to distinguish among heritable fragile sites, constitutive fragile sites, and nonspecific telomeric structural changes.

RFLP for intron E of factor XI gene

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