The clinical utility of PGD with HLA matching: a collaborative multi-centre ESHRE study.

STUDY QUESTION: Has PGD-HLA been successful relative to diagnostic and clinical efficacy? SUMMARY ANSWER: The diagnostic efficacy of PGD-HLA protocols was found lower in this study in comparison to published PGD-HLA protocols and to that reported for general PGD by ESHRE (78.5 vs 94.1% and vs 92.6%, respectively), while the clinical efficacy has proven very difficult to assess due to inadequate follow-up of both the ART/PGD and HSCT procedure outcomes. WHAT IS KNOWN ALREADY: The first clinical cases for PGD-HLA were reported in 2001. It is now a well-established procedure, with an increasing number of cycles performed every year. However, PGD-HLA is still offered by relatively few PGD centres, the currently available data is fragmented and most reports on PGD-HLA applications are limited in number and scope. Published systematic details on methodology, diagnostic results, overall ART success and haematopoietic stem cell transplantation (HSCT) outcomes are limited, precluding an evaluation of the true clinical utility of PGD-HLA cycles. STUDY DESIGN, SIZE, DURATION: This retrospective multi-centre cohort study aimed to investigate the diagnostic and clinical efficacy of the PGD-HLA procedure and the aspects of PGD-HLA cycles influencing positive outcomes: birth of genetically suitable donor-baby (or babies) and HSCT. In April 2014, 32 PGD centres (Consortium members and non-members) with published/known PGD-HLA activity were invited to participate. Between February and September 2015, 14 centres submitted their data, through a custom-designed secure database, with unique login access for each centre. Data parameters covered all aspects of PGD-HLA cycles (ART, embryology and genetic diagnosis), donor-babies born and HSCT. PARTICIPANTS/MATERIALS, SETTING, METHODS: From 716 cycles submitted by 14 centres (performed between August 2001 and September 2015), the quality evaluation excluded 12 cycles, leaving 704, from 364 couples. The online database, based on REDCap, a free, secure, web-based data-capture application, was customized by Centre for Clinical Epidemiology and Outcomes Research (CLEO), Athens. Continuous variables are presented using mean, standard deviation, median and interquartile range, and categorical variables are presented as absolute and relative frequencies. MAIN RESULTS AND THE ROLE OF CHANCE: The data included 704 HLA-PGD cycles. Mean maternal age was 33.5 years. Most couples (81.3%) requested HLA-typing with concurrent exclusion of a single monogenic disease (58.6% for beta-thalassaemia). In 92.5% couples, both partners were fertile, with an average 1.93 HLA-PGD cycles/couple. Overall, 9751 oocytes were retrieved (13.9/cycle) and 5532 embryos were analysed (7.9/cycle). Most cycles involved fresh oocytes (94.9%) and Day 3 embryo biopsy (85.3%). In 97.5% of cycles, the genotyping method involved PCR only. Of 4343 embryos diagnosed (78.5% of analysed embryos), 677 were genetically suitable (15.4% of those analysed for HLA alone, 11.6% of those analysed for HLA with exclusion of monogenic disease). Of the 364 couples, 56.6% achieved an embryo transfer (ET) and 598 embryos were transferred in 382 cycles, leading to 164 HCG-positive pregnancies (pregnancy rate/ET 41.3%, pregnancy rate/initiated cycle 23.3%) and 136 babies born (live birth rate/ET 34.3%, live birth rate/initiated cycle 19.3%) to 113 couples. Data analysis identified the following limitations to the overall success of the HLA-PGD procedure: the age of the mother undergoing the treatment cycle, the number of oocytes collected per cycle and genetic chance. HSCT was reported for 57 cases, of which 64.9% involved combined umbilical cord-blood and bone marrow transplantation from the HLA-identical sibling donor; 77.3% of transplants reported no complications. LIMITATIONS REASONS FOR CAUTION: The findings of the study may be limited as not all PGD centres with PGD-HLA experience participated. Reporting bias on completion of the online database may be another potential limitation. Furthermore, the study is based on retrospective data collection from centres with variable practices and strategies for ART, embryology and genetic diagnosis. WIDER IMPLICATIONS OF THE FINDINGS: This is the first multi-centre study evaluating the clinical utility of PGD-HLA, indicating variations in practice and outcomes throughout 15 years and between centres. The study highlights parameters important for positive outcomes and provides important information for both scientists and couples interested in initiating a cycle. Above all, the study underlines the need for better collaboration between all specialists involved in the ART-PGD/HLA procedure, as well as the need for comprehensive and prospective long-term data collection, and encourages all specialists to aim to properly evaluate and follow-up all procedures, with the ultimate aim to promote best practice and encourage patient informed decision making. STUDY FUNDING/COMPETING INTEREST(S): The study wishes to acknowledge ESHRE for funding the customization of the REDCap database. There are no competing interests. TRIAL REGISTRATION NUMBER: N/A.

Clinical and molecular consequences of disease-associated de novo mutations in SATB2.

PURPOSE: To characterize features associated with de novo mutations affecting SATB2 function in individuals ascertained on the basis of intellectual disability. METHODS: Twenty previously unreported individuals with 19 different SATB2 mutations (11 loss-of-function and 8 missense variants) were studied. Fibroblasts were used to measure mutant protein production. Subcellular localization and mobility of wild-type and mutant SATB2 were assessed using fluorescently tagged protein. RESULTS: Recurrent clinical features included neurodevelopmental impairment (19/19), absent/near absent speech (16/19), normal somatic growth (17/19), cleft palate (9/19), drooling (12/19), and dental anomalies (8/19). Six of eight missense variants clustered in the first CUT domain. Sibling recurrence due to gonadal mosaicism was seen in one family. A nonsense mutation in the last exon resulted in production of a truncated protein retaining all three DNA-binding domains. SATB2 nuclear mobility was mutation-dependent; p.Arg389Cys in CUT1 increased mobility and both p.Gly515Ser in CUT2 and p.Gln566Lys between CUT2 and HOX reduced mobility. The clinical features in individuals with missense variants were indistinguishable from those with loss of function. CONCLUSION: SATB2 haploinsufficiency is a common cause of syndromic intellectual disability. When mutant SATB2 protein is produced, the protein appears functionally inactive with a disrupted pattern of chromatin or matrix association.Genet Med advance online publication 02 February 2017.

One-cell biopsy significantly improves the outcome of preimplantation genetic diagnosis (PGD) treatment: retrospective analysis of 569 PGD cycles at the Stockholm PGD centre.

STUDY QUESTION: What are the significant factors that influence the outcome of a PGD treatment? SUMMARY ANSWER: The age of the woman and the number of biopsied cells per embryo are of significant importance for a successful PGD treatment. WHAT IS KNOWN ALREADY: Younger women are more likely to succeed with an IVF treatment. STUDY DESIGN, SIZE, DURATION: Cohort study, retrospective analysis of 569 PGD cycles, 1996-2009. PARTICIPANTS, SETTING, METHODS: 256 couples and 569 PGD treatments at 'Stockholm PGD centre'. At this centre after 2003, a 1-cell policy was applied, when possible, with respect to the reliability of the diagnostic test and since 2009, 1-cell biopsy policy was also applied for monogenic disorders. MAIN RESULTS AND THE ROLE OF CHANCE: The women under 36 years of age were three times more likely to get pregnant after PGD treatment, P = 0.003 and odds ratio 3.1 [95% confidence interval (CI) 1.5-6.5]. The 1-cell biopsy cycles were twice as likely to result in a pregnancy in comparison with cycles were 2 cells were removed from the embryo, P = 0.0013 and odds ratio 2.55 (95% CI 1.44-4.52). No other factors were found to be significant for the outcome. LIMITATIONS, REASONS FOR CAUTION: Retrospective analysis with 1- and 2-cell biopsies at different times. WIDER IMPLICATIONS OF THE FINDINGS: The results will have an impact on the implementation of PGD in general, thereby making it possible to significantly improve the treatment outcome.

High white matter lesion load is associated with hippocampal atrophy in mild cognitive impairment.

BACKGROUND: Mild cognitive impairment (MCI) is a heterogeneous condition suggested as a prodromal state of Alzheimer's disease (AD) and subcortical vascular dementia (SVD). Recent findings suggest that white matter lesions (WML) may be associated with hippocampal atrophy. The objective of the study was to examine hippocampal and WML volumes in MCI patients and to examine if WML were linked to hippocampal atrophy. METHODS: The Gothenburg MCI study is a clinically based longitudinal study with biennial clinical assessments. The participants (n = 166) consist of 92 patients with stable MCI, 30 patients with converting MCI, and 44 healthy controls. WML volumes was measured manually using MRIcron. Automated segmentation of hippocampal and total white matter volumes was performed using FreeSurfer. RESULTS: The patients converting from MCI to dementia had reduced hippocampal volume. Stable MCI patients had fewer WML and converting MCI patients had more WML compared to controls. Hippocampal volume was only correlated to WML volume (ρ = 0.57; p < 0.01) in the quartile (n = 42) with the most WML. CONCLUSIONS: Hippocampal atrophy is present in both AD and SVD. Hippocampal volume was associated with WML volume only in the high WML quartile, suggesting that the WML volume must reach a threshold before hippocampal atrophy is seen.

Improved structural characterization of chromosomal breakpoints using high resolution custom array-CGH.

Array-CGH is a powerful tool for the rapid detection of genomic imbalances. By customizing the array it is possible to increase the resolution in a targeted genomic region of interest and determine the structure of the breakpoints with high accuracy, as well as to detect very small imbalances. We have used targeted custom arrays to zoom in on 38 chromosomal breakpoints from 12 different patients carrying both balanced and unbalanced rearrangements. We show that it is possible to characterize unbalanced breakpoints within 17-20,000 bp, depending on the structure of the genome. All of the deletion and duplication breakpoints were further refined and potential underlying molecular mechanisms of formation are discussed. In one of seven carriers of apparently balanced reciprocal translocations we detected a small deletion of 200 bp within the previously FISH-defined breakpoint, and in another patient, a large deletion of 11 Mb was identified on a chromosome not involved in the translocation. Targeted custom oligonucleotide arrays make it possible to perform fine mapping of breakpoints with a resolution within the breakpoint region much higher compared to commercially available array platforms. In addition, identification of small deletions or duplications in apparently balanced rearrangements may contribute to the identification of new disease causing genes.

Detailed molecular and clinical characterization of three patients with 21q deletions.

We have investigated three patients with 21q deletions, two with developmental delay, dysmorphic features and internal organ malformations, and one with cognitive function within the normal range but with some deficits in gross and fine motor development. All aberrations were characterized by array-comparative genomic hybridization (array-CGH). In addition, extensive fluorescence in situ hybridization (FISH) mapping on metaphase chromosomes and mechanically stretched chromosomes was performed on patient 1 who had an extremely complex intrachromosomal rearrangement with 16 breakpoints, four deletions and four duplications. Patients 2 and 3 had interstitial deletions comprising 21q21.1-21q22.11 and 21q11.2-21q21.3, respectively. Partial deletions of 21q are rare and these patients display a highly variable phenotype depending on the size and position of the deletion. A review of the literature identified 38 cases with pure 21q deletions. Twenty-three of these had reliable mapping data. The combined information of present and previous cases suggests that the ITSN1 gene is involved in severe mental retardation in patients with 21q deletion. In addition, a critical region of 0.56 Mb containing four genes, KCNE1, DSCR1, CLIC6 and RUNX1, is associated with severe congenital heart defects, and deletions of the most proximal 15-17 Mb of 21q is associated with mild or no cognitive impairment, but may lead to problems with balance and motor function.

Combination of hippocampal volume and cerebrospinal fluid biomarkers improves predictive value in mild cognitive impairment.

BACKGROUND: Mild cognitive impairment (MCI) is a heterogeneous condition, and the prognosis differs within the group. Recent findings suggest that hippocampal volumetry and CSF biomarkers can be used to predict which MCI patients have an underlying neurodegenerative disorder. OBJECTIVE: To examine the combined predictive value of hippocampal volume and CSF levels of total tau (T-tau) and beta-amyloid(42) (Abeta(42)) in stable and converting MCI patients. The participants (n = 68) included patients with MCI at baseline and who converted to dementia by the time of the 2-year follow-up (n = 21), stable MCI patients (n = 21) and healthy controls (n = 26). METHODS: The Göteborg MCI study is a clinically based longitudinal study with biannual clinical assessments. Hippocampal volumetry was performed manually, based on data from the 0.5-tesla MRI investigations at baseline. Baseline CSF levels of T-tau and Abeta(42) were measured using commercially available, enzyme-linked immunosorbent assays. RESULTS: The converting MCI group had significantly smaller left hippocampi, lower CSF Abeta(42) and higher T-tau compared to both the stable MCI group and the healthy controls. Multivariate analysis revealed that a combination of the variables outperformed the prognostic ability of the separate variables. CONCLUSIONS: Hippocampal volumes supplement the prognostic accuracy of CSF Abeta(42) and T-tau in MCI.

Padlock probes: circularizing oligonucleotides for localized DNA detection.

Nucleotide sequence information derived from DNA segments of the human and other genomes is accumulating rapidly. However, it frequently proves difficult to use such short DNA segments to identify clones in genomic libraries or fragments in blots of the whole genome or for in situ analysis of chromosomes. Oligonucleotide probes, consisting of two target-complementary segments, connected by a linker sequence, were designed. Upon recognition of the specific nucleic acid molecule the ends of the probes were joined through the action of a ligase, creating circular DNA molecules catenated to the target sequence. These probes thus provide highly specific detection with minimal background.

Concurrent microdeletion and duplication of 22q11.2.

Microduplication of 22q11.2 has been reported in fewer than 40 cases, all of them including the DiGeorge critical region (DGCR). We here present the characterization of a new duplication that does not include the DGCR. The duplication was initially found by multiplex ligation-dependent probe amplification analysis of 22q11.2 in a young girl with a concurrent deletion of the DGCR in 70% of her peripheral blood lymphocytes. Her phenotype included many of the features of the velocardiofacial syndrome, with velopharyngeal insufficiency, recurrent infections, learning and concentration problems as well as difficulties in social interactions. However, there were no congenital malformations, and her facial appearance was not typical for the syndrome. Further investigations included array comparative genomic hybridization (CGH) to size map the deletion/duplication and interphase fluorescent in situ hybridization to investigate mosaicism and the structure of the rearrangement. An identical duplication of this part of 22q11.2 has not been reported before, and the duplication itself seems to be associated with very mild or no symptoms. This study contributes to the growing knowledge regarding new deletions and duplications of 22q11.2, most of them mediated by the pre-disposing high number of low-copy repeats in the region.

Small baseline volume of left hippocampus is associated with subsequent conversion of MCI into dementia: the Göteborg MCI study.

BACKGROUND: Earlier studies have reported that hippocampal atrophy can to some extent predict which patients with mild cognitive impairment (MCI) will subsequently convert to dementia, and that converters have an enhanced rate of hippocampal volume loss. OBJECTIVE: To further validate the hypothesis that hippocampal atrophy predicts conversion from MCI to dementia, to relate baseline hippocampal volume to different forms of dementia, and to investigate the role of hippocampal side differences and rate of volume loss over time. PATIENTS: The subjects (N=68) include patients with MCI at baseline and progression to dementia at the two-year follow-up (N=21), stable MCI patients (N=21), and controls (N=26). Among the progressing patients, 13 were diagnosed as having AD. METHODS: The Göteborg MCI study is a clinically based longitudinal study with biannual clinical assessments. Hippocampal volumetry was performed manually on the MRI investigations at baseline and at the two-year follow-up. RESULTS: Hippocampal volumetry could predict conversion to dementia in both the AD and the non-AD subgroup of converters. Left hippocampal volume in particular discriminated between converting and stable MCI. Cut off points for individual discrimination were shown to be potentially useful. The converting MCI group had a significantly higher rate of hippocampal volume loss as compared to the stable MCI group. CONCLUSIONS: In MCI patients, hippocampal volumetry at baseline gives prognostic information about possible development of AD and non-AD dementia. Contrary to earlier studies, we found that left hippocampal volume has the best predictive power. Reliable predictions appear to be possible in many individual cases.

Detecting Genes with Ligases

The combination of synthetic oligonucleotide probes and DNA ligases is central to several recently developed genetic assays. Among the advantages of ligase-mediated gene detection is that ligation of probe pairs provides highly specific detection of unique DNA sequences in genomic samples. The technique also allows for convenient distinction between sequence variants, since mismatched bases at the junction of the probe pair prevent ligation. Moreover, the circumstance that two probes are joined into one molecule can be exploited for detection in several ways, for instance by observing the change in probe size upon ligation. Alternatively, a detectable function on one probe can be demonstrated to become linked to a retrievable function on another one through ligation. Ligation products can also be recruited as templates for subsequent ligation reactions in powerful amplification schemes. So-called padlock probes lock to their targets by encircling them, remaining in place even after denaturing washes. Here, we will describe two ligase-mediated assays: one that serves to monitor the presence of common sequence variants in amplified samples of genomic DNA and another that is suitable to detect localized gene sequences.

Presence of an IDS-related locus (IDS2) in Xq28 complicates the mutational analysis of Hunter syndrome.

A deficiency of the enzyme iduronate-2-sulfatase (IDS) is the cause of Hunter syndrome (mucopolysaccharidosis type II). Here, we report a study of the human IDS locus at Xq28. An unexpected finding was an IDS-related region (IDS2) which is located on the telomeric side of the IDS gene within 80 kb. We have identified sequences in this locus that are homologous to exons 2 and 3 as well as sequences homologous to introns 2, 3 and 7 of the IDS gene. The exon 3 sequences in the IDS gene and in the IDS2 locus showed 100% identity. The overall identities of the other identified regions were 96%. A locus for DXS466 was also found to be located close to IDS2. The existence of the IDS2 locus complicates the diagnosis of mutations in genomic DNA from patients with Hunter syndrome. However, information about the IDS2 locus makes it possible to analyze the IDS gene and the IDS2 locus separately after PCR amplification.

Strong founder effect for the fragile X syndrome in Sweden.

We analyzed the FRAXAC2 and DXS548 microsatellites in normal and fragile X chromosomes from Sweden and the Czech Republic in order to investigate a possible founder effect for chromosomes carrying a fragile X mutation. We report a much stronger linkage disequilibrium between the marker haplotypes and the disease in Swedish fragile X chromosomes than in Czech and most other previously studied Caucasian populations. Two haplotypes accounted for 64% of Swedish fragile X chromosomes and for only 14% of normal chromosomes. Neither of these two haplotypes was found in Czech chromosomes, but the most common Swedish fragile X haplotype is the same as that reported to be predominant in Finnish fragile X patients. Linkage disequilibrium was observed in the Czech fragile X chromosomes but the haplotypes were more diverse and similar to those observed in other Caucasian populations. The most prevalent Swedish fragile X haplotype was traced back from affected males to common ancestors in the early 18th century. This indicates an apparently silent segregation of fragile X alleles through up to nine generations. The geographical distribution of the two major at-risk haplotypes in Sweden suggests that they were present among early settlers in different parts of the country.

New X-linked syndrome with severe mental retardation, severely impaired vision, severe hearing defect, epileptic seizures, spasticity, restricted joint mobility, and early death.

A family with an X-linked mental retardation syndrome involving seven children in two generations is reported. The syndrome includes microcephaly, severe mental retardation, optic atrophy with severely impaired vision or blindness, a severe hearing defect, spasticity, epileptic seizures, restricted movement of the large joints, and death in infancy or early childhood. We conclude that this is a distinct, previously unrecognized X-linked mental retardation syndrome.

Infantile autism--fragile X: molecular findings support genetic heterogeneity.

Twenty-two members of 18 families with autism have been examined for the presence of mutations and abnormal methylation in the FMR-1 region at Xq27.3. All patients fulfilled diagnostic criteria of infantile autism. A characteristic pattern of insertion and methylation were detected after Southern blot analysis in 7 autistic individuals expressing the fragile site at Xq27.3. Normal DNA patterns were observed in 15 autistic boys cytogenetically negative for the fragile site. The results indicate a lack of involvement of the FMR-1 region in infantile autists negative for fragile X expression.

Carrier detection of the fragile X syndrome using flanking loci DXS98, DXS105, and DXS304.

Diagnosis of the carrier status of the fragile X [fra(X)] syndrome was made in 2 unrelated women who did not express the fragile site. Both were related to several individuals with a typical fra(X) phenotype and the marker X chromosome. A restriction fragment length polymorphism (RFLP) approach was used with probes that flank the fra(X) locus (FRAXA). The loci used for risk calculations of the fra(X) genotype were DXS98 and DXS105 on the centromeric side and a recently characterized locus, DXS304, on the telomeric side. Coincidence correction for the distances between marker loci and FRAXA was made according to the Kosambi function. The DNA marker test gave the risk for one female to be a carrier of 99.7-99.9%. In another family a female was excluded from being a carrier with a probability of greater than 99.7%. The DNA marker U6.2, defining the locus DXS304, has increased the reliability of DNA based diagnosis of carrier status for females-at-risk. It is concluded that DNA analysis can serve as a valuable complement to chromosome analysis in families informative for the more closely linked flanking markers.

Methylation and mutation patterns in the fragile X syndrome.

Chromosomes carrying the mutation causing the fragile X [fra(X)] syndrome have been shown to have an unstable DNA sequence close to or within the fragile site. The length variation is located within a DNA fragment containing a CGG trinucleotide repeat which is unstable in both mitosis and meiosis. We have used the probe StB12.3 from the region to analyze the mutations and the methylation patterns in 21 families segregating for the fra(X) syndrome. Among 40 fra(X) males all showed an abnormal pattern. The normal 2.8 kb band was absent in 36 individuals and replaced by a heterogeneous smear of larger size. The remaining four were shown to be "mosaics" with the presence of both mutated, unmethylated and mutated, methylated fragments. We found four normal transmitting males, one which was a great-grandson of another normal transmitting male indicating that the pre-mutation can remain stable through two meioses in the female. In nine fra(X) positive females the abnormal pattern consisted of a smear, usually seen in affected males, in addition to the normal bands. Five of these females were mentally normal. Of clinical importance is the prediction of mental impairment in females. We suggest that this is not made by the detection of the full mutation alone, but rather by the degree of methylation of the normal X chromosome. Our results suggest that difference of clinical expression in monozygotic twins may be correlated with difference in methylation pattern. Six out of 33 fra(X) negative females at risk were diagnosed as carriers. Our observations indicate that molecular heterogeneity is responsible for variable expression of the fra(X) syndrome in both males and females.

Pharmacokinetics of dipotassium chlorazepate in patients after repeated 50 mg oral doses.

Dipotassium chlorazepate (DPC) was administered to ten patients (five males and five females), ages 18-37 years (mean 27.4), as a once daily dose of 50 mg until a steady state was reached. Plasma concentrations of the main metabolite N-desmethyldiazepam (DMD) were monitored by a high pressure liquid chromatographic (HPLC) method during the medication period and for 5 days after withdrawal of the drug. The plasma half life (t1/2), the elimination coefficient (K beta), the steady state concentration (Css), and the apparent volume of distribution (V beta), were calculated at steady state and the mean values +/- SEM were 44 +/- 5 h. 0.0184 +/- 0.0026 h(-1), 1590 +/- 163 ng/ml and 1.41 +/- 0.17 l/kg, respectively. A moderate inter-individual variability was observed. There was no tendency towards dose dependent elimination.

Comparison studies of chlorazepate administered as a divided daily dose and as a single dose at night.

The residual effects of dipotassium chlorazepate administered as either a single daily dose of 20 mg at bedtime or a divided daily dose (5 + 5 + 10 mg) were studied in a placebo-controlled, double-blind trial comprising 12 out-patients. The following tests were used to determine changes in perceptual wakefulness, performance ability, fine motor skills, and coordination: critical flicker fusion test, car driving in a simulator, and the "bead and needle tests." In addition, the patients underwent a clinical assessment and also filled out a self-rating scale for judging factors related to the tests. No significant differences were found between the dosage schedules or between the active medication and the placebo. The clinical results were not dependent on the dosage schedule.

Pharmacokinetics of N-desmethyldiazepam in healthy volunteers after single daily doses of dipotassium chlorazepate.

Dipotassium chlorazepate was administered to 12 healthy volunteers (8 males and 4 females), aged 22-38 years, as a single daily dose of 20 mg for 14 days. Plasma concentrations of N-desmethyldiazepam were monitored with a gas-chromatographic method during the medication period and for 5 days after withdrawal of the drug. The plasma half-life (t1/2), the elimination coefficient (Kbeta), the concentration (Css), and the apparent volume of distribution (Vbeta) were calculated at steady state, and the mean values +/- SEM were 53 +/- 6 h, 0.0147 +/- 0.0013 h-1, 884 +/- 73 ng/ml, and 1.13 +/- 0.08 1/kg, respectively. A moderate interindividual variability was observed regarding these parameters. There was no tendency toward a biexponential elimination. A significant difference in the apparent volume of distribution was found when males and females were compared.