Longitudinal karyotype and genetic signature analysis of cultured human colon adenocarcinoma cell lines LS180 and LS174T.

Giemsa-banded chromosomes were analyzed at intervals during either 34 or 70 serial subcultivations of two cell lines, LS180 and LS174T, established from one primary human colon adenocarcinoma, and at passage 14 of autochthonous normal bowel cells, NB(LS174T). The cell lines were established and subcultured by either scraping or trypsin treatment of primary cultures; the scraped cell line was designated LS180, and the trypsin-dispersed cell line was named LS174T. Early passages of LS174T cells were composed mainly of 46,XX (38%) and 45,X (34%) karyotypes; LS180 cultures possessed cells with 46,XX (54%), 45,X (7.5%), and 47,XX+D (19.5%) chromosome modes. In both cell lines, the 45,X karyotype predominated in later subcultivations. After the fifth passage, all LS180 cells examined exhibited a translocation from the long arm of the X chromosome to the long arm of the No. 5 chromosome. Cultures from the patient's normal bowel mucosa and peripheral blood leukocytes had normal 46,XX karyotypes. Genetic signature analysis sustantiated the common genetic origin of the cell lines, and we concluded that differences observed between LS180 and LS174T were not due to contamination with other cell lines. LS180 and LS174T represent closely related cell lines differing cytogenetically in a translocation.

Ganglioneuroblastoma and fetal hydantoin-alcohol syndromes.

A ganglioneuroblastoma developed in a 35-month-old boy with both the fetal hydantoin and fetal alcohol syndromes. Our case, plus two recent reports in the literature, would very likely establish the relationship between fetal hydantoin syndrome and the development of neural crest tumors. Infants exposed in utero to hydantoins should be closely observed for the development of these tumors.

Mendelian inheritance of isolated nonsyndromic cleft palate.

Isolated, apparently nonsyndromic cleft palate (CP) is thought to be etiologically heterogeneous. The multifactorial threshold explanation for CP is postulated in most cases. Mendelian inheritance has been documented in 3 families. We report on three unrelated white families with 17 relatives in several generations affected with CP, including submucous CP and bifid/absent uvula. We could find no evidence of a cleft syndrome. In one family, the pattern is consistent with autosomal dominant inheritance. In 2 families, the pattern is consistent with X-linked recessive inheritance. The specific findings and their implications for family evaluation and genetic counseling are discussed.

Hemifacial microsomia and variants: pedigree data.

Ear malformations occur per se or together with other congenital anomalies. Many syndromes with ear malformations have been described. We have studied propositi with hemifacial microsomia (HFM) or Goldenhar syndrome (GS), also called oculoauriculovertebral "dysplasia" (OAV). In addition to ear malformations some individuals may have a small and/or malformed mandible, epibulbar, or conjunctival lipodermoids and anomalies of the cervical spine. Other malformations may also be seen. At present, the cause of these disorders is unclear. Here we present pedigree data on 97 propositi, 44 of whom had a family history of the same or similar anomaly. First-degree relatives were most often affected (35/433, 8%). Of 176 sibs tabulated, 11 (6%) were considered affected. The pattern of occurrence in many families suggested multifactorial determination, although other interpretations are possible. The occurrence of differing anomalies within a family suggests that the disorders constitute a single entity. The most frequent anomaly was a mild ear malformation (preauricular node or tag). This suggests a broad phenotypic spectrum. These data are useful for purposes of genetic counseling.

Growth hormone insufficiency associated with haploinsufficiency at 18q23.

Growth hormone insufficiency is a common cause of growth failure in children with the 18q- syndrome. Individuals with this syndrome have a deletion as large as 36 Mb from the long arm of chromosome 18. We have evaluated 33 children with this syndrome for growth hormone production and have identified a region of approximately 2 Mb, which is deleted in every growth hormone insufficient patient. Two genes contained in this region, myelin basic protein, and the galanin receptor, are candidate genes for the growth hormone insufficiency phenotype.

Proximal 7q interstitial deletion in a severely mentally retarded and mildly abnormal infant.

We describe a boy with an interstitial deletion of 7q [46,XY,del(7)(pter-->q11.21::q11.23-->qter)] and severe mental retardation, bilateral inguinal hernias, plagiocephaly, and mildly abnormal facial appearance. This is the 21st case report involving a proximal 7q deletion, but the first report of this specific deletion in the absence of Zellweger syndrome. Specific genotype-phenotype correlations are still not possible for this region of chromosome 7.

Oculoauriculovertebral dysplasia and variants: phenotypic characteristics of 294 patients.

Here we describe the phenotypic characteristics of a single craniofacial clinic population of 294 individuals affected with oculoauriculovertebral dysplasia (OAV) and variants. To our knowledge, this is the largest population so described in the literature. The study population was divided into five subgroups based on the presence of combinations of minimal diagnostic criteria: microtia, mandibular hypoplasia, anomalies of the cervical spine and/or epibulbar or lipodermoids. The following data were recorded: sex (M:F 191:103); race (78% Caucasian); the presence of unilateral or bilateral microtia (193 unilateral, 98 bilateral); the presence of symmetric microtia in bilateral cases (34/98); the presence of mandibular hypoplasia ipsilateral or contralateral to the microtic ear or most severely microtic ear in bilateral cases (135/137 were ipsilateral in unilateral cases, 55/62 were ipsilateral in bilateral cases); the number of individuals with no other congenital anomaly in addition to the minimal diagnostic criteria (154/294), with only one other congenital anomaly (51/294), and with two or more other congenital anomalies (89/294); and the type of other congenital anomalies. Finally, we compared our results with other studies. Findings from our study include: mandibular asymmetry should be expected in patients with unilateral or bilateral microtia; bilateral involvement is frequent in patients with microtia; other malformations are seen frequently in all subgroups; anomalies of the cervical spine are more likely to be associated with other anomalies; and other malformations are seen in all systems and should be searched for to provide optimal management.

Short-limb dwarfism and hypertrophic cardiomyopathy in a patient with paternal isodisomy 14: 45,XY,idic(14)(p11).

Uniparental disomy (UPD) has been shown to result in specific disorders either due to imprinting and/or homozygosity of mutant alleles. Here we present the findings in a child with paternal UPD14. Ultrasound evaluation was performed at 30 weeks of gestation because of abnormally large uterine size. Pertinent ultrasound findings included polyhydramnios, short limbs, abnormal position of hands, small thorax, and nonvisualization of the fetal stomach. Post-natally the infant was found to have a low birth weight, short birth length, contractures, short limbs, and a small thorax with upslanting ribs. Assisted ventilation and gastrostomy were required. At age 6 months, the infant required hospitalization for hypertrophic cardiomyopathy which responded to Atenolol. Initial cytogenetic studies demonstrated an apparently balanced de novo Robertsonian translocation involving chromosomes 14 and a karyotype designation of 45,XY,t(14q14q). No indication of mosaicism for trisomy 14 was observed in metaphase spreads prepared from peripheral blood lymphocytes or skin-derived fibroblasts. C-band and fluorescence in situ hybridization results demonstrated that the chromosome was dicentric. DNA analyses showed paternal uniparental isodisomy for chromosome 14. Based on the cytogenetic and DNA results a final karyotype designation of 45,XY,idic(14)(p11) was assigned to this infant with paternal isodisomy of chromosome 14.

Preferential loss of the paternal alleles in the 18q- syndrome.

Individuals with the 18q- syndrome have variable deletions from the long arm of chromosome 18. They also exhibit a highly variable phenotype. To correlate genotype with phenotype accurately, extensive molecular and phenotypic analyses are needed on each affected individual. As a part of this analysis, we have determined the parental origin of the deleted chromosome in 34 individuals with the 18q- syndrome. We have found that 85% of the de novo deletions are paternal in origin. The percentage of fathers of individuals with paternally derived deletions who were > 30 years old was (not significantly) greater than that of the general population. The mothers of individuals with maternally derived deletions were near an average age for childbearing compared to the general population. Individuals with maternally derived terminal deletions had breakpoints as varied as those with paternally derived deletions. These results are consistent with the hypothesis that the reduced incidence of maternally derived deletions is not due to reduced viability, since individuals with large maternally derived deletions of chromosome 18q were found. We hypothesize that the prevalence of paternally derived deletions is due to an increased frequency of chromosome breakage in male germ cells. These results are consistent with results observed in other segmental aneusomies in which there is a high incidence of paternally derived deletions.

Microtia and associated anomalies: statistical analysis.

Terms such as oculoauriculovertebral dysplasia, Goldenhar syndrome, and hemifacial microsomia have been used to describe microtia with specific combinations of other craniofacial anomalies. Microtia is also observed with anomalies of postcranial structures. Statistical studies were performed on 297 patients with microtia and other anomalies to identify subgroups of patients representing previously described or new associations. Analysis identified 15 subgroups of patients with specific patterns of anomalies. Log-linear analyses of cranial and postcranial variables demonstrated a positive association between mandibular hypoplasia and cervical spine fusion, which was, in turn, positively associated with other spine anomalies (P less than .02) and other skeletal anomalies (P less than .001). Although unilateral microtia was commonly observed with mandibular hypoplasia, mandibular hypoplasia was negatively associated with bilateral microtia. Many of the associated anomalies were of structures not derived from the 1st and 2nd branchial arch neural crest. However, most associated anomalies were of structures derived from migratory cell populations or populations undergoing differentiation prior to migration between the 19th and 24th day post-fertilization (neural crest, ectodermal placode, mesoderm, surface ectoderm). These findings suggest that many different cell populations may be disturbed in the pathogenesis of microtia in association with other anomalies. The timing of the pathogenetic event may determine the specific pattern of associated anomalies.

Oculoauriculovertebral anomaly: segregation analysis.

Seventy-four families of probands with oculoauriculovertebral anomaly were evaluated, including 116 parents and 195 offspring. Relatives were examined to identify ear malformations, mandibular anomalies, and other craniofacial abnormalities. For segregation analysis using POINTER, selection of the sample was consistent with single ascertainment. Different population liabilities were used for probands and relatives, because affection was narrowly defined for probands and broadly defined for relatives. The hypothesis of no genetic transmission was rejected. The evidence favored autosomal dominant inheritance; recessive and polygenic models were not distinguishable.

Growth hormone deficiency associated in the 18q deletion syndrome.

The 18q- syndrome is one of the commonest deletion syndromes. Clinical characteristics are variable but may include: hypotonia, tapered digits, "carp-like" mouth, mental retardation, and hearing impairment. Growth failure (GF; both weight and height < 3%) was reported in 80% of affected individuals. We evaluated growth hormone (GH) sufficiency in 5 18q- syndrome patients, 3 of whom had growth failure (< 3% weight and height); the remaining 2 had normal growth parameters. Laboratory evaluation of growth included measurement of IGF-1, IGFBP-3, bone ages and GH response to pituitary provocative agents. Three patients failed to produced adequate GH following stimulation testing. Of 3 patients with inadequate GH production, 1 had normal growth (above 3%). Only 1 of 5 patients had normal GH production and normal growth parameters. Our findings to date suggest that GH deficiency is common in individuals with the 18q- syndrome. The pathogenesis of this finding is unknown. We postulate that a gene(s) on 18q is involved in GH production.

Congenital anomalies and anthropometry of 42 individuals with deletions of chromosome 18q.

Deletions of chromosome 18q are among the most common segmental aneusomies compatible with life. The estimated frequency is approximately 1/40,000 live births [Cody JD, Pierce JF, Brkanac Z, Plaetke R, Ghidoni PD, Kaye CI, Leach RJ. 1997. Am. J. Med. Genet. 69:280-286]. Most deletions are terminal encompassing as much as 36 Mb, but interstitial deletions have also been reported. We have evaluated 42 subjects with deletions of 18q at our institution. This is the largest number of individuals with this chromosome abnormality studied by one group of investigators. Here we report the physical findings in these individuals. We have compared our findings with those of previously reported cases and have found a significantly different incidence of several minor anomalies in our subjects. We also describe here several anomalies not previously reported in individuals with deletions of 18q, including short frenulum, short palpebral fissures, disproportionate short stature, overlap of second and third toes, and a prominent abdominal venous pattern. Characteristics found in subjects were analyzed for correlation with cytogenetic breakpoints. Several traits were found to correlate with the extent of the deletion. Large deletions were associated with significantly decreased head circumference and ear length as well as the presence of proximally placed and/or anomalous thumbs. Individuals with the smallest deletions were more likely to have metatarsus adductus. Although relatively few genotype/phenotype correlations were apparent, these data demonstrate that correlations with breakpoint are possible. This implies that more correlations will become evident when the more precise molecularly based genotyping is completed. These correlations will identify critical regions on the chromosome in which genes responsible for specific abnormal phenotypes are located.

Magnetic resonance imaging demonstrates incomplete myelination in 18q- syndrome: evidence for myelin basic protein haploinsufficiency.

Magnetic resonance imaging (MRI) and MRI relaxometry were used to investigate disturbed brain myelination in 18q- syndrome, a disorder characterized by mental retardation, dysmorphic features, and growth failure. T1-weighted and dual spin-echo T2-weighted MR images were obtained, and T1 and T2 parametric image maps were created for 20 patients and 12 controls. MRI demonstrated abnormal brain white matter in all patients. White matter T1 and T2 relaxation times were significantly prolonged in patients compared to controls at all ages studied, suggesting incomplete myelination. Chromosome analysis using fluorescence in situ hybridization techniques showed that all patients with abnormal MRI scans and prolonged white matter T1 and T2 relaxation times were missing one copy of the myelin basic protein (MBP) gene. The one patient with normal-appearing white matter and normal white matter T1 and T2 relaxation times possessed two copies of the MBP gene. MRI and molecular genetic data suggest that incomplete cerebral myelination in 18q- is associated with haploinsufficiency of the gene for MBP.

Congenital migratory ichthyosiform dermatosis with neurologic and ophthalmologic abnormalities.

We encountered two patients with a congenital migratory ichthyosiform dermatosis, retinal colobomas, conductive hearing loss, seizures, mental retardation, and similar facial features. The results of electron microscopic studies performed on skin biopsy specimens from the patients differed significantly from those of previously reported cases of ichthyosiform dermatoses with associated neurologic and ophthalmologic abnormalities; they appear to represent a new neuroectodermal syndrome.

Measuring contributions to the research mission of medical schools.

The authors of this article, who were the members and staff of a research panel formed by the AAMC as part of its mission-based management initiative, reflect on the growing interest in quantitative information in the management of the research mission of medical schools. They note the serious limitations of any such system of measures for research, particularly its inability to represent directly the quality of the research effort. Despite these concerns, the authors acknowledge that leaders in academic medicine have always used quantitative measures in one form or another to compare performance or assess progress. Two factors appear to be driving increases in this practice: (1) the need to demonstrate to institutional stakeholders that resources are being used wisely and that the school's performance justifies continued investment in the research mission; and (2) the need to fashion an economic strategy to manage precious institutional resources, particularly research space. Given these realities, the authors offer guidelines for the proper development and use of measures to assess contributions by faculty, departments, and institutions to the research mission. They also comment on the measures most commonly used in four areas: grants and other revenue-generating activities; publications; faculty members' research reputation and contributions to the national research enterprise; and support to the general research mission of the school. The authors conclude that quantitative information can help institutional leaders in important management decisions. However, the potential for misuse is great. The key is always to regard this information as an aid to judgment, not a substitute for it.

Classification, etiology, and genetic aspects of craniofacial anomalies.

The shape and function of the cranium and face at birth are the end-products of complex and poorly understood developmental processes. In this article I will attempt first to review normal craniofacial development, believing that this basic information is essential to the understanding of abnormal development. I will then review a scheme of classification of anomalies based on etiologic considerations, illustrating each etiologic factor with conditions encountered in practice. Genetic principles in the etiology of craniofacial anomalies will be emphasized. Because of space constraints, no attempt will be made to catalogue syndromes of craniofacial anomalies. The reader is referred to standard reference texts for such comprehensive listings.

Genetic service delivery: infrastructure, assessment and information.

Identification of genomic determinants of complex disorders such as cancer, diabetes and cardiovascular disease has prompted public health systems to focus on genetic service delivery for prevention of these disorders, adding to their previous efforts in birth defects prevention and newborn screening. This focus is consistent with previously identified obligations of the public health system as well as the core functions of public health identified by the Institute of Medicine. Models of service delivery include provision of services by the primary care provider in conjunction with subspecialists, provision of services through the medical home with co-management by genetics providers, provision of services in conjunction with disorder-specific treatment centers, and provision of services through a network of genetics clinics linked to medical homes. Whatever the model for provision of genetic services, tools to assist providers include facilities for outreach and telemedicine, information technology, just-in-time management plans, and emergency management tools. Assessment tools to determine which care is best are critical for quality improvement and development of best practices. Because the workforce of genetics providers is not keeping pace with the need for services, an understanding of the factors contributing to this lag is important, as is the development of an improved knowledge base in genomics for primary care providers.