The economics of clinical genetics services. III. Cognitive genetics services are not self-supporting.

We investigated the amount of time required to provide, and the charges and reimbursement for, cognitive genetics services in four clinical settings. In a prenatal diagnostic center, a mean of 3 h/couple was required to provide counseling and follow-up services with a mean charge of $30/h and collection of $27/h. Only 49% of personnel costs were covered by income from patient charges. In a genetics clinic in a private specialty hospital, 5.5 and 2.75 h were required to provide cognitive services to each new and follow-up family, respectively. The mean charge for each new family was $25/h and for follow-up families $13/h. The amount collected was less than 25% of that charged. In a pediatric genetics clinic in a large teaching hospital, new families required a mean of 4 h and were charged $28/h; follow-up families also required a mean of 4 h, and were charged $15/h. Only 55% of the amounts charged were collected. Income from patient charges covered only 69% of personnel costs. In a genetics outreach setting, 5 and 4.5 h were required to serve new and follow-up families, respectively. Charges were $25/h and $12/h, and no monies were collected. In all clinic settings, less than one-half of the total service time was that of a physician, and more than one-half of the service time occurred before and after the clinic visit. In no clinic setting were cognitive genetics services self-supporting. Means to improve the financial base of cognitive genetics services include improving collections, increasing charges, developing fee schedules, providing services more efficiently, and seeking state, federal, and foundation support for services.     

The economics of clinical genetics services. IV. Financial impact of outpatient genetic services on an academic institution.

Those clinical genetic services that do not involve laboratory tests or procedures--i.e., the "cognitive" services such as diagnosis, management, and counseling--are labor-intensive, time-consuming, and not self-supporting. However, as a result of an evaluation at a genetics clinics, a patient will often receive other services at the same medical center. The full economic impact of the genetics clinic may be underappreciated. Therefore, at one medical center we examined (a) three settings that delivered genetics services and (b) two specialty clinics providing services to children with genetics conditions; and we calculated charges and payments for an unselected, consecutive group of outpatients. The results showed that cognitive genetics services accounted for a variable, but generally low, percentage of both the professional (generally physicians') and total charges accumulated by patients as a consequence of their visit to the genetics clinic. With laboratory and procedural charges included, patients seen in general genetics clinics (or their insurance plans) paid up to three times as much to the medical center and to its health professionals as to the genetics professional. These data confirm that clinical genetics services, while not generating enough income to cover their own costs, bring considerable revenue to the medical center. This fact alone should prove useful to the director of clinical genetics programs when they are negotiating finances with institutional administrators.     

Evolutionary genetics: The economics of mutation.

The presence of mutator genotypes in populations of bacteria may be favoured by selection because they produce rare beneficial mutations and thereby increase the rate of adaptive evolution. Recent work, however, shows that the relationship between mutation rates and adaptive evolution is more complicated.     

The genetics of phenotypic plasticity I. Heritability

Methods for estimating the genetic component of phenotypic plasticity are presented. In the general case of clonal replicates or full-sibs raised in several environments, the heritability of plasticity can be measured as the ratio of the genotype-environment interaction variance to the total phenotypic variance. In the special case of only two environments plasticity also can be measured as the difference among environments in genotype or family means. In that case, the heritability of plasticity can be measured as either a ratio of variance components or as the slope of a parent-offspring regression. The general measure suffers because no least-square standard errors have been developed, although they can be calculated by maximum-likelihood or bootstrapping techniques. For the other two methods least-square standard errors can be calculated but require very large experiments for statistical significance to be achieved. The heritability measures are compared using data on plasticity of thorax size in response to temperature in Drosophila melanogaster. The heritability estimates are all in close agreement. Models of the evolution of phenotypic plasticity have treated it as a trait in its own right and as a cross-environment genetic correlation. Although the first approach is the one used here, neither one is preferred.     

The genetics of Otosclerosis. I. Distorted sex ratio.

The offspring of 214 otosclerotic x normal couples were investigated, and within these sibships, the segregation of otosclerosis is compatible with autosomal dominant inheritance. However, the overall sex ratio is approximately 0.73, with otosclerosis being approximately 1.8 times more frequent in female offspring. These observations are interpreted as the consequence of selection against males carrying the otosclerosis gene. Elimination of such males occurs only in certain sibships. The remaining families demonstrate a sex ratio approximating unity with similar rates of otosclerosis in both sexes. This selection operates mainly, and possibly only, prenatally.     

Genetic variation in Nigeria. I. The genetics of phenylthiourea tasting ability.

Phenylthiourea (PTC) taste sensitivity thresholds have been measured for 2,013 Nigerians using a modified sorting technique. The frequency of non-tasters was observed to be 12.5% and the t gene frequency was 0.354. There was a significant difference between the sexes at the 0.01 level for the overall population. However, when the data are analyzed according to the geographical origin of the subject, the sex difference is found only in one of three geographical regions. Also, there may be geographical influences on PTC taste sensitivity, although this was not statistically significant. The estimates reported in this population differ considerably from some of the previously published estimates for black populations.