Kathryn F. Peters

A Mosaic Activating Mutation in AKT1 Associated with the Proteus Syndrome

BACKGROUND The Proteus syndrome is characterized by the overgrowth of skin, connective tissue, brain, and other tissues. It has been hypothesized that the syndrome is caused by somatic mosaicism for a mutation that is lethal in the nonmosaic state. METHODS We performed exome sequencing of DNA from biopsy samples obtained from patients with the Proteus syndrome and compared the resultant DNA sequences with those of unaffected tissues obtained from the same patients. We confirmed and extended an observed association, using a custom restriction-enzyme assay to analyze the DNA in 158 samples from 29 patients with the Proteus syndrome. We then assayed activation of the AKT protein in affected tissues, using phosphorylation-specific antibodies on Western blots. RESULTS Of 29 patients with the Proteus syndrome, 26 had a somatic activating mutation (c.49G→A, p.Glu17Lys) in the oncogene AKT1, encoding the AKT1 kinase, an enzyme known to mediate processes such as cell proliferation and apoptosis. Tissues and cell lines from patients with the Proteus syndrome harbored admixtures of mutant alleles that ranged from 1% to approximately 50%. Mutant cell lines showed greater AKT phosphorylation than did control cell lines. A pair of single-cell clones that were established from the same starting culture and differed with respect to their mutation status had different levels of AKT phosphorylation. CONCLUSIONS The Proteus syndrome is caused by a somatic activating mutation in AKT1, proving the hypothesis of somatic mosaicism and implicating activation of the PI3K-AKT pathway in the characteristic clinical findings of overgrowth and tumor susceptibility in this disorder. (Funded by the Intramural Research Program of the National Human Genome Research Institute.).

The relationship of nondirectiveness to genetic counseling: report of a workshop at the 2003 NSGC Annual Education Conference.

Nondirectiveness has been a guiding principle for genetic counseling since the founding of the profession. However, its efficacy and appropriateness in this role have been frequently questioned. A workshop at the 2003 Annual Education Conference of the National Society of Genetic Counselors provided audience participation in a discussion of these issues. Participants presented arguments for and against nondirectiveness as a central ethos. They described complex personal transitions in adapting what they had learned about nondirectiveness during training to the realities of the workplace. There was support for flexible approaches to genetic counseling, with varying adherence to nondirectiveness, based on client and family needs and values, clinical circumstances, and desired counseling outcomes. The discussion supports the use of clinical experience, outcomes research, and the experience of other professions to move beyond nondirectiveness and more accurately identify the theoretical bases that underlie genetic counseling in the variety of circumstances in which it is currently practiced.

A comparison of the background, needs, and expectations of patients seeking genetic counseling services

Patient background, needs, and expectations (BNE) can be important predictors and modifiers of the process and outcomes of genetic counseling. We describe the assessment of BNE of 216 genetic counseling clients using the BNE Scale. Twenty‐five percent sought reproductive genetic counseling (RGC), 57% sought adult‐pediatric genetic counseling (APGC), and 18% sought cancer genetic counseling (CaGC). Analyses of the BNE of these patient groups identified significant differences in general unsureness/uncertainty about their condition (df = 2, F = 3.96, Significance = 0.02), beliefs about treatment for the condition (df = 2, F = 3.352, Significance = 0.04), and interest in support group involvement (df = 2, F = 4.6, Significance = 0.01). Respondents who had not had genetic counseling more readily endorsed the desire to address educational issues than those who had previously had genetic counseling (Previous GC: Mean = 4.03, SD = 0.67; No Previous GC: Mean = 4.29, SD = 0.61; t‐value; −2.86; P < 0.01). These results suggest that there are significant differences in the BNE of groups of patients seeking genetic counseling. These data support differential genetic counseling goal setting based on practice subspecialty, as well as sustain the requirement of broad based clinical training in genetic counseling. Further, these data provide additional evidence of the reliability and validity of the BNE Scale to characterize groups of individuals eligible for genetic counseling.

Comparison of the background, needs, and expectations for genetic counseling of adults with experience with Down syndrome, Marfan syndrome, and neurofibromatosis†

We describe an analysis of the responses of 605 adults with experience with Down syndrome, Marfan syndrome, or neurofibromatosis (NF) to the BNE Scale, a scale specifically designed to assess the background, needs, and expectations (BNE) of genetic counseling patients. Significant group differences were found. Specifically, the respondents in the Down syndrome group reported more favorable beliefs about the condition and the availability of social support than the respondents in the other groups. Respondents in the NF group reported more unsureness about their condition and a greater need for genetic information than members of the other groups. Notably, having positive feelings about the condition was negatively correlated with support group interest for respondents of the Marfan syndrome group (r = −0.159, P < 0.01). Having an affected child was associated with interest in health provider input (t = −3.4; P = 0.001) and the desire to talk about psychosocial issues (t = −2.9; P = 0.004). However, previous experience with genetic counseling was not found to affect BNE. These results support the usefulness of the BNE Scale to compare the BNE of patient groups, as well as provide important insight into the BNE of individuals seeking counseling about Down syndrome, Marfan syndrome, and NF.

Twin Gestation Pregnancies: Genetic Counseling and Testing Experience

We report on the prenatal genetic counseling and testing experience in 343 pregnancies with twin or higher multiple gestations. By self-report, 8% (27/343) parents of these pregnancies reported meeting with a genetic counselor, and 23% (79/343) elected prenatal genetic testing. The most common testing procedures elected were maternal serum analyte screening and amniocentesis to identify fetuses with aneuploidy or neural tube defects. Use of prenatal genetic testing was correlated with advanced maternal age. No association was found between use of genetic testing and use of OI/ART or the length of time needed to conceive. Forty percent (11/27) of those who met with a genetic counselor opted to decline prenatal testing/screening. These data suggest that although clients with multiple gestation pregnancies would likely benefit from genetic counseling, many are not availing themselves of this service. Implications of these data for the genetic counseling profession are discussed.

An Opportunity for Genetic Counseling Intervention: Depression in Parents of Individuals with Proteus Syndrome.

Depression is common, affecting 2–5% of the general population. Parental depression can confound adjustment to, and caring for, a child with a genetic condition. As part of a study on psychosocial issues of parents caring for children with Proteus syndrome, 31 parents (20 mothers and 11 fathers) completed a depression screening tool, the Beck Depression Inventory. Approximately 23% (4/20 mothers and 3/11 fathers) scored positive on the tool. Pessimism, sense of failure, general lack of satisfaction, sense of punishment, self-dislike, social withdrawal, indecisiveness, work inhibition, somatic preoccupation, and loss of libido were reported more frequently by the group of parents with positive screen results than those with normal results. These data suggest that symptoms of depression may be prevailing among parents of individuals with Proteus syndrome. Because effective interventions for depression are readily available, genetic counselors working with families affected with rare, overgrowth disorders should specifically assess parents for physical and affective symptoms of depression and refer them for appropriate clinical treatment.