Association of the missense variant p.Arg203Trp in PACS1 as a cause of intellectual disability and seizures.

Graphical abstract key: ADHD, attention deficit hyperactivity disorder; ASD, atrial septal defect; DD, developmental delay; EEG, electroencephalogram; Ht, height; ID, intellectual disability; OCD, obsessive-compulsive disorder; OFC, open fontanelle; PDA, patent ductus arteriosis; PFO, patent foramen ovale; VSD, ventricular septal defect; Wt, weight.

Practical considerations in the clinical application of whole-exome sequencing.

Despite the exciting advent of whole-exome sequencing (WES) in medical genetics practices, the optimal interpretation of results requires further actions such as reconsidering clinical information and obtaining further laboratory testing. There are no published data to guide clinicians in this process. In a retrospective study on 93 patients who underwent clinical WES, we set out to assess and resolve these practical challenges. With the laboratories reporting a molecular diagnostic rate of 25.8%, the medical geneticists and the laboratories were 90% concordant in their interpretation of the WES results. Divergence occurred when the medical geneticist reconsidered clinical information and/or additional information regarding pathogenicity of a variant. Variants of uncertain significance were reported in 86% of patients, with 53.7% needing follow-up, such as additional laboratory tests and genotyping of family members. By layering clinical data (e.g. mode of inheritance and phenotypic fit) on to the laboratory results, we developed clinical categories for the WES results. These categories of definite diagnosis (14/93), likely diagnosis (8/93), possible diagnosis (13/93) and no diagnosis (58/93) could be used to convey results to patients uniformly. Our framework for a clinically informed interpretation of the results enhances the utility of WES within medical genetics practices.

Social cognitive training in adolescents with chromosome 22q11.2 deletion syndrome: feasibility and preliminary effects of the intervention.

BACKGROUND: Children with chromosome 22q11.2 deletion syndrome (22q11DS) often have deficits in social cognition and social skills that contribute to poor adaptive functioning. These deficits may be of relevance to the later occurrence of serious psychiatric illnesses such as schizophrenia. Yet, there are no evidence-based interventions to improve social cognitive functioning in children with 22q11DS. METHODS: Using a customised social cognitive curriculum, we conducted a pilot small-group-based social cognitive training (SCT) programme in 13 adolescents with 22q11DS, relative to a control group of nine age- and gender-matched adolescents with 22q11DS. RESULTS: We found the SCT programme to be feasible, with high rates of compliance and satisfaction on the part of the participants and their families. Our preliminary analyses indicated that the intervention group showed significant improvements in an overall social cognitive composite index. CONCLUSIONS: SCT in a small-group format for adolescents with 22q11DS is feasible and results in gains in social cognition. A larger randomised controlled trial would permit assessment of efficacy of this promising novel intervention.

Indicators of anxiety and depression in women with the fragile X premutation: assessment of a clinical sample.

BACKGROUND: Current research suggests that depression and anxiety may be common problems in women with the fragile X (FMR1) premutation. METHODS: To learn more about this in a clinical setting, we asked 33 women with the FMR1 premutation and 20 women without the FMR1 premutation to complete the Brief Carroll Depression Scale (Brief CDS) and the Multidimensional Anxiety Questionnaire (MAQ) and to provide information about mental health medication use. Questionnaire findings were compared between groups and with normative samples. Trinucleotide (CGG) repeat counts were also correlated to checklist findings. RESULTS: Both women with the FMR1 premutation and the comparison group had high current mental health medication use (33% vs. 35%). Approximately 1/3 of the women from both groups had high Brief CDS Total T-scores (33% vs. 30%). More women with the FMR1 premutation had at least one elevated MAQ Total or sub-scale T-score than the comparison group (39% vs. 10%, P = 0.03). Twenty-one per cent of women with the FMR1 premutation had all three of the indicators of distress targeted in this study vs. none of the women in the comparison samples (P < 0.05). There was no statistically significant correlation between CGG repeat size and abnormal checklist findings using the Spearman rank correlation, although a higher percentage of women with >100 CGG repeats (57%) had an elevated Brief CDS Total T-score than women with 100 CGG repeats also had all three indicators of anxiety and depression (P = 0.03). CONCLUSIONS: Women with the FMR1 premutation appear to have a high incidence of depression and increased symptoms of anxiety. Screening tools like the Brief CDS and the MAQ may be useful to identify these women in the clinic setting. Positive identification could lead to increased mental health care and treatment.

Longitudinal study of the carrier testing process for fragile X syndrome: perceptions and coping.

This paper reports the results of a longitudinal study of women at-risk to inherit the fragile X mutation. It addresses 1) how upsetting the women perceived their carrier information to be, 2) how serious a problem they perceive fragile X syndrome to be, and 3) descriptions of feelings about the carrier testing process. The study sample consisted of 42 women (20 carriers and 22 noncarriers). There were two measurement times (just prior to carrier testing and after learning actual carrier status). The measures used were a Fragile X Visual Analog Scale and a structured interview. At time 1, being at-risk was reported to be upsetting and fragile X syndrome was perceived to be a serious problem. For the women found to be carriers there was no change from time 1 to time 2 on any of the items. Significant change occurred in the non-carriers. They were significantly less upset at time 2 after receiving the results of their carrier test than at time 1. They also perceived fragile X syndrome to be a more serious problem than they did at time 1 and a more serious problem than the carriers at time 2. Themes found included concerns that carrier status for fragile X syndrome presented a barrier for having healthy biological children and concern for children's and grandchildren's adaptation to their own carrier status. Coping behaviors were activated to manage the emotions related to these concerns. The coping behaviors identified were minimization, acceptance of the possibility of being a carrier, a sense of being able to deal with the outcome of the carrier test, positive comparison, problem solving, and positive interpretation.

Carrier testing in fragile X syndrome: effect on self-concept.

The purpose of the study was to explore self-concept in women at risk for inheriting the fragile X mutation. Time 1 measures were obtained prior to carrier testing and Time 2 measures were collected approximately 5 months after learning carrier status. The sample consisted of 42 women from 17 families. Measures included the Tennessee Self-Concept Scale (TSCS), the fragile X Visual Analog Scale (VAS), and a structured interview. The TSCS provided a global measure of self-concept and the fragile X VAS and structured interview provided a contextual measure of self related to carrier status. Results indicated that there were no differences initially between carriers and noncarriers and no change from Time 1 to Time 2 on the TSCS. Analysis of the Time 1 fragile X VAS means for the total sample found a reduction in positive feelings about self. Analysis of the Time 2 fragile X VAS found that noncarriers reported improvement in feelings about self, with no change in feelings about self found in the carriers. Responses from the structured interview indicated that the feelings regarding self in the context of genetic testing are not related to global self-concept, but result from concerns regarding the implications of a positive carrier test for themselves and their families. This information highlights areas related to carrier testing that warrant further investigation and may ultimately result in modifications to the genetic counseling.

Threat to Parental Role: A Possible Mechanism of Altered Self-Concept Related to Carrier Knowledge.

Researchers and clinicians have suggested that learning one is a carrier for a genetic disorder has the potential to alter self-concept. Concerns about self-concept have influenced the development of policies regarding the availability of carrier testing for minors and the informed-consent process. A literature review identified three mechanisms through which self-concept has been proposed to be affected: altered perception of genetic identity, diminished social identity, and an altered perception of health. This paper presents a conceptual framework developed from identity theory and the "self's response to threat" to propose a fourth mechanism: threat to the parental role. Clarification of the role of self-concept, the threat to self-concept related to carrier knowledge, and coping behaviors activated in response to this threat would help to target appropriate genetic counseling interventions.

Genetic Counseling for Fragile X Syndrome: Recommendations of the National Society of Genetic Counselors.

The National Society of Genetic Counselors' (NSGC) recommendations for fragile X syndrome (FXS) genetic counseling are intended to assist health care professionals who provide genetic counseling for individuals and families in whom the diagnosis of FXS is strongly suspected or has been made. The recommendations are the opinions of genetic counselors with expertise in FXS counseling and are based on clinical experience, a review of pertinent English language medical articles, and reports of expert committees. These recommendations should not be construed as dictating an exclusive course of management, nor does use of such recommendations guarantee a particular outcome. These recommendations do not displace a health care provider's professional judgment based on the clinical circumstances of a particular client.

Prenatal diagnosis of glycogen storage disease type IV using PCR-based DNA mutation analysis.

Deficiency of glycogen branching enzyme activity causes glycogen storage disease type IV (GSD-IV). Clinically, GSD-IV has variable clinical presentations ranging from a fatal neonatal neuromuscular disease, to a progressive liver cirrhosis form, and to a milder liver disease without progression. Current methods for prenatal and postnatal diagnosis are based on an indirect method of measuring the enzyme activity, which has a limited sensitivity and cannot be used to distinguish patients with these variable clinical phenotypes. In this study, a GSD-IV family with a non-progressive hepatic form of the disease requested prenatal diagnosis. Determination of the branching enzyme activity in cultivated amniocytes showed 20 per cent residual activity overlapping with the level detected in the heterozygotes. Mutation analysis revealed that the fetus carried two mutant alleles, L224P and Y329S, the same as the proband of this family. The fetus was predicted to be affected and postnatally his clinical presentation is consistent with the diagnosis. We conclude that DNA mutation analysis should be used in the prenatal diagnosis of GSD-IV, especially in the situation of high residual enzyme activity.

Parental attitudes regarding carrier testing in children at risk for fragile X syndrome.

Sixty-five parents of individuals affected by fragile X syndrome who attended the National Fragile X Conference in Portland, Oregon (1996), were asked to complete a survey assessing parental level of concern about carrier testing in children at risk for fragile X syndrome. All subjects completed a 15-item paper and pencil Likert response scale measure that was developed specifically for this study. The items included parental rights and duties, psychological adjustment, adaptation, discrimination, harm, childbearing, and interpersonal relationships. The major concern of the parents was that their children have knowledge of their carrier status prior to becoming sexually active and that their children be able to marry informed of their genetic risk. Mothers were significantly more concerned than fathers about raising their children with the knowledge of their carrier status. A sense of parental right to make the decision regarding carrier testing for children was associated with concerns about (1) behavioral or educational problems, (2) knowledge of carrier status prior to sexual activity or marriage, and (3) adjustment of the children to knowledge of their carrier status. As the sample was drawn from a unique population of parents, the results of this survey should be interpreted with caution. The findings of this study suggest a model of parents providing anticipatory guidance for their children to help them adjust to carrier information and for their children to have this knowledge prior to the possibility of reproduction.

Genetic Counseling-Stress, Coping, and the Empowerment Perspective.

Historically one of the basic foundations of the genetic counseling process has been nondirectiveness; however, its definition and utility continues to be in question. There remains a need to develop genetic counseling interventions in order to qualify, quantify, measure, and enhance the genetic counseling process as well as to delineate the complex interactions of education and counseling that occur. We propose a framework for genetic counseling interventions utilizing an empowerment perspective and Lazarus and Folkman's adaptation of the theory of stress and coping. This model frames the genetic counseling process as one that promotes the autonomy of the individual by providing the individual with the tools required to make their own decisions and enhances coping and adjustment to the outcome of those decisions through control and mastery.

A gene on chromosome 11q23 coding for a putative glucose- 6-phosphate translocase is mutated in glycogen-storage disease types Ib and Ic.

Glycogen-storage diseases type I (GSD type I) are due to a deficiency in glucose-6-phosphatase, an enzymatic system present in the endoplasmic reticulum that plays a crucial role in blood glucose homeostasis. Unlike GSD type Ia, types Ib and Ic are not due to mutations in the phosphohydrolase gene and are clinically characterized by the presence of associated neutropenia and neutrophil dysfunction. Biochemical evidence indicates the presence of a defect in glucose-6-phosphate (GSD type Ib) or inorganic phosphate (Pi) (GSD type Ic) transport in the microsomes. We have recently cloned a cDNA encoding a putative glucose-6-phosphate translocase. We have now localized the corresponding gene on chromosome 11q23, the region where GSD types Ib and Ic have been mapped. Using SSCP analysis and sequencing, we have screened this gene, for mutations in genomic DNA, from patients from 22 different families who have GSD types Ib and Ic. Of 20 mutations found, 11 result in truncated proteins that are probably nonfunctional. Most other mutations result in substitutions of conserved or semiconserved residues. The two most common mutations (Gly339Cys and 1211-1212 delCT) together constitute approximately 40% of the disease alleles. The fact that the same mutations are found in GSD types Ib and Ic could indicate either that Pi and glucose-6-phosphate are transported in microsomes by the same transporter or that the biochemical assays used to differentiate Pi and glucose-6-phosphate transport defects are not reliable.

Prenatal diagnosis and carrier detection for glycogen storage disease type III using polymorphic DNA markers.

Deficiency of glycogen debranching enzyme gene (AGL) causes glycogen storage disease type III (GSD-III), an autosomal recessive disease. Prenatal diagnosis and carrier detection using enzymatic methods are technically difficult and have limited ability to distinguish a carrier from an affected patient. Mutations in the AGL gene can be used for these purposes. However, the mutations identified thus far account for less than half of the total mutant alleles, and no common mutations have been detected except in North African Jews and in a rare subtype of the disease (GSD-IIIb). Our recent identification of three highly informative DNA polymorphic markers in the AGL gene allowed us to perform prenatal diagnosis and carrier detection in two GSD-III families with unknown mutations, using the polymerase chain reaction (PCR) and restriction analysis. In one family, a fetus was diagnosed to be a GSD-III carrier and his carrier status was confirmed postnatally. A newborn in the second family was postnatally diagnosed with the disease.

Carrier testing in the fragile X syndrome: attitudes and opinions of obligate carriers.

This study surveyed obligate carriers of the fragile X syndrome fra(X) to ascertain opinions and attitudes regarding carrier testing. Female carriers of fra(X) syndrome were recruited during their visits to the Fragile X Clinic at Duke University Medical Center. Twenty-eight obligate carriers completed a 48 question structured interview and a visual analog scale (VAS). Strong trends in the responses were identified. Fra(X) syndrome was viewed as a very serious problem and the risk to offspring high. Subjects reported that prior knowledge of carrier status would have changed their reproductive plans. All felt that relatives should be informed about the inheritance of fra(X) syndrome; the mean age given for preferred age to inform their children of the inheritance of fra(X) syndrome was 12 years, and mean age given for optimal timing of carrier testing was 10 years. The women interviewed indicated that growing up with knowledge of their carrier status would have been preferable to learning this information as adults and they endorsed an aggressive approach to informing and testing their children. Further investigation is warranted to determine the psychological consequences of carrier testing for fra(X) syndrome in order to develop appropriate guidelines for testing and informing individuals at risk for fra(X) syndrome.

A fragile X male with a broad smear on Southern blot analysis representing 100-500 CGG repeats and no methylation at the EagI site of the FMR-1 gene.

Fragile X DNA studies were carried out on all obligate carriers of a large fragile X family with 10 mentally retarded individuals. One 64-year-old carrier man with an altered FMR-1 allele was not described as being mentally retarded or as having any limitations in function. He was married, raised 8 children, and worked as an auto mechanic. On examination, he had macrocephaly and mild macroorchidism but few of the other typical physical findings of males with fragile X syndrome. His Full Scale IQ is 73, and his Vineland Adaptive Behavior Composite is 73. On the Woodcock-Johnson Psycho-Educational Battery-Revised, he achieved standard scores of 64 in Reading, 55 in Math, and 83 in Knowledge. His DNA findings showed a broad smear on Southern blot analysis of 100-500 CGG repeats and no methylation at the EagI site upstream of the FMR-1 protein coding region. His FMR-1 protein production is 12% of normal. His daughters all have large premutations, with somatic instability in the size of the CGG repeat lengths. They all have evidence of academic underachievement and 2 have physical characteristics frequently described in individuals with fragile X.

Clinical and laboratory findings in four patients with the non-progressive hepatic form of type IV glycogen storage disease.

The classic clinical presentation for type IV glycogen storage disease (branching enzyme deficiency, GSD IV) is hepatosplenomegaly with failure to thrive occurring in the first 18 months of life, followed by progressive liver failure and death by age 5 years. Although there have been two patients without apparent liver progression previously reported, no long-term follow-up clinical data have been available. We present here the clinical spectrum of the non-progressive liver form of GSD IV in four patients, and long-term follow-up of the oldest identified patients (ages 13 and 20 years). None has developed progressive liver cirrhosis, skeletal muscle, cardiac or neurological involvement, and none has been transplanted. Branching enzyme activity was also measured in cultured skin fibroblasts from patients with the classic liver progressive, the early neonatal fatal, and the non-progressive hepatic presentations of GSD IV. The residual branching enzyme activity in the patients without progression was not distinguishable from the other forms and could not be used to predict the clinical course. Our data indicate that GSD IV does not always necessitate hepatic transplantation and that caution should be used when counselling patients regarding the prognosis of GSD IV. Patients should be carefully monitored for evidence of progression before recommending liver transplantation.

Dissemination of genetic risk information to relatives in the fragile X syndrome: guidelines for genetic counselors.

Fragile X Syndrome, which affects 1 in 1,250 males, is the most common inherited condition causing mental retardation. Although carrier detection for the fragile X syndrome utilizing DNA has now been simplified, genetic counseling and the process of informing at-risk family members remains complex. The purpose of this paper is to offer practical guidelines to health professionals providing genetic counseling to fragile X families in order to facilitate the dissemination of genetic risk information to relatives. This paper was developed from a workshop held at the 4th International Fragile X Conference. The guidelines presented here represent a beginning in the development of an approach to informing relatives in fragile X families about genetic risk, and the identification of mechanisms to reduce the burden to families.

Fryns syndrome survivors and neurologic outcome.

Fryns syndrome is an autosomal recessive multiple congenital anomaly syndrome characterized by diaphragmatic hernia, unusual facies, and distal limb hypoplasia. It was first reported as a lethal condition. We report on a three-year-old survivor with Fryns syndrome, and provide a review on the outcome of other survivors. Patients who survive the neonatal period represent 14% of reported cases. Characteristics of survivors include less frequent diaphragmatic hernia and milder lung hypoplasia, absence of complex cardiac malformation, and neurologic impairment. Multiple central nervous system abnormalities have been reported in Fryns syndrome, including agenesis of the corpus callosum, Dandy-Walker abnormality, cerebellar heterotopias, cerebellar hypoplasia, enlarged ventricles, and hypoplasia of the olfactory bulbs. Our patient exhibited profound mental retardation. He had malformations of gyration and sulcation, particularly around the central sulcus, and hypoplastic optic tracts beyond the optic chiasm. Understanding of long-term outcome of survivors is important for counseling of families with Fryns syndrome. Careful brain examination is advised; however, a normal radiological brain examination does not preclude developmental delay. The spectrum of individual outcome and of associated anomalies indicates that individual evaluation, including imaging for structural brain malformation, is strongly advised.

Genetic basis of glycogen storage disease type 1a: prevalent mutations at the glucose-6-phosphatase locus.

Diagnosis of glycogen storage disease (GSD) type 1a currently is established by demonstrating the lack of glucose-6-phosphatase (G6Pase) activity in the patient's biopsied liver specimen. Recent cloning of the G6Pase gene and identification of mutations within the gene that causes GSD type 1a allow for the development of a DNA-based diagnostic method. Using SSCP analysis and DNA sequencing, we characterized the G6Pase gene of 70 unrelated patients with enzymatically confirmed diagnosis of GSD type 1a and detected mutations in all except 17 alleles (88%). Sixteen mutations were uncovered that were shown by expression to abolish or greatly reduce G6Pase activity and that therefore are responsible for the GSD type 1a disorder. R83C and Q347X are the most prevalent mutations found in Caucasians, 130X and R83C are most prevalent in Hispanics, and R83H is most prevalent in Chinese. The Q347X mutation has thus far been identified only in Caucasian patients, and the 130X mutation has been identified only in Hispanic patients. Our results demonstrate that the DNA-based analysis can accurately, rapidly, and noninvasively detect the majority of mutations in GSD type 1a. This DNA-based diagnosis now permits prenatal diagnosis among at-risk patients and serves as a database in screening and counseling patients clinically suspected of having this disease.

Hemangioma, supraumbilical midline raphé, and coarctation of the aorta with a right aortic arch: single causal entity?

Most congenital cutaneous hemangiomas are a sporadic occurrence. Hemangiomas have been found in association with coarctation of the aorta and a right aortic arch. A separate association has been noted of midline ventral defects with hemangiomas. We report on a patient with multiple hemangiomas, coarctation of the aorta and a right aortic arch, a superaumbilical midabdominal raphé and sternal cleft. Our patient represents an overlap between these two conditions. Review of the literature identified four additional patients with a similar combination of anomalies. The clinical overlap between these 5 patients suggests that they are variants of the same conditions and represent a spectrum of defects that includes hemangiomas, midline ventral defects, aortic arch abnormalities and brain malformation.