A Wolf in Hiding: Epilepsy and Post-ictal Psychosis As Unrecognized Presenting Features of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder that affects multiple organ systems. Many patients present with neurological and psychiatric signs and symptoms at some point in the course of the disease. Here, we present a patient with neuropsychiatric SLE (NPSLE) who presented with long-standing and difficult-to-control epileptic seizures and post-ictal psychotic symptoms prior to the diagnosis of SLE. A 39-year-old patient with a ten-year history of uncontrolled epileptic seizures despite multiple medications and recent diagnosis of chronic kidney disease presented to the emergency department following multiple witnessed seizures. Her seizures were controlled following initial interventions and the patient was admitted to the hospital to control metabolic acidosis and hyperkalemia. Later, the patient developed psychosis with auditory hallucinations, combative behavior, and agitation which were controlled with restraints and sedatives. Initial serological and urinary studies revealed disturbances of multiple systems and triggered broad workup resulting in positive serological SLE markers. The patient was then started on immunosuppressive medications with prompt control of post-ictal psychosis. The patient was discharged with immunosuppressive regimen and control of her seizures. This case highlights that signs and symptoms of NPSLE may appear before the onset of SLE diagnosis. Additionally, our patient had long-standing epilepsy with post-ictal psychosis, which has not been reported in the literature before. We believe this case highlights the challenges in the diagnosis of NPSLE, the rapid control of seizures and/or psychosis with SLE treatment, and the necessity to broaden the differential diagnosis in atypical presentation of seizures and/or psychosis.

Chasing the Cup: A Comprehensive Review of Spinal Cord Injuries in Hockey

Ice hockey is a high-speed sport with a high rate of associated injury, including spinal cord injury (SCI). The incidence of hockey-related SCI has increased significantly in more recent years. A comprehensive literature search was conducted with the PubMed, Medline, Google Scholar, and Web of Science databases using the phrases “hockey AND spinal cord injuries” to identify relevant studies pertaining to hockey-related SCIs, equipment use, anatomy, and biomechanics of SCI, injury recognition, and return-to-play guidelines.

Fifty-three abstracts and full texts were reviewed and included, ranging from 1983 to 2021. The proportion of catastrophic SCIs is high when compared to other sports. SCIs in hockey occur most commonly from a collision with the boards due to intentional contact resulting in axial compression, as well as flexion-related teardrop fractures that lead to spinal canal compromise and neurologic injury. Public awareness programs, improvements in equipment, and rule changes can all serve to minimize the risk of SCI.

Hockey has a relatively high rate of associated SCIs occurring most commonly due to flexion-distraction injuries from intentional contact. Further investigation into equipment and hockey arena characteristics as well as future research into injury recognition and removal from and return to play is necessary.

White matter integrity after cannabidiol administration for treatment resistant epilepsy

OBJECTIVE

The effects of individual cannabinoids on white matter integrity are unclear. Human studies have shown white matter maturation alterations in regular recreational cannabis users with the magnitude of these effects dependent on the age of exposure. However, studies have yet to determine which phytocannabinoids are most responsible for these changes. In the current study, we analyzed the effects of pharmaceutical grade cannabidiol oral solution (CBD; Epidiolex® in the U.S.; Epidyolex® in the EU; 100 mg/mL oral solution) on white matter integrity using diffusion MRI in patients with treatment resistant epilepsy (TRE).

METHODS

15 patients with TRE underwent 3 T diffusion MRI prior to receiving CBD and then again approximately 12 weeks later while on a stable dose of CBD for at least two weeks. DTI analyzes were conducted using DSI Studio and tract-based spatial statistics (TBSS).

RESULTS

DTI analysis using DSI Studio showed significant increases in fractional anisotropy (FA) in the right medial lemniscus (p = 0.03), right superior cerebellar peduncle (p = 0.03) and the pontine crossing tract (p = 0.04); decreased mean diffusivity (MD) in the left uncinate fasciculus (p = 0.02) and the middle cerebellar peduncle (p = 0.04); decreased axial diffusivity (AD) in the left superior cerebellar peduncle (p = 0.05), right anterior limb of the internal capsule (p = 0.03), and right posterior limb of the internal capsule (p = 0.02); and decreased radial diffusivity (RD) in the middle cerebellar peduncle (p = 0.03) and left uncinate fasiculus (p = 0.01). The follow-up ANCOVA also yielded significant results when controlling for covariates of CBD dosage, age, sex, change in seizure frequency, and scanner type: FA increased in the pontine crossing tract (p = 0.03); RD decreased in the middle cerebellar peduncle (p = 0.04) and left uncinate fasciculus (p = 0.04). Subsequent TBSS analysis controlling for the same variables yielded no significant white matter differences between groups.

CONCLUSION

These findings indicate relatively minor short-term effects of highly-purified plant-derived CBD on white matter structural integrity in patients with TRE.

Cannabidiol normalizes resting-state functional connectivity in treatment-resistant epilepsy

OBJECTIVE

Resting-state (rs) network dysfunction is a contributing factor to treatment resistance in epilepsy. In treatment-resistant epilepsy (TRE), pharmacological and nonpharmacological therapies have been shown to improve such dysfunction. In this study, our goal was to prospectively evaluate the effect of highly purified plant-derived cannabidiol (CBD; Epidiolex®) on rs functional magnetic resonance imaging (fMRI) functional connectivity (rs-FC). We hypothesized that CBD would change and potentially normalize the rs-FC in TRE.

METHODS

Twenty-two of 27 participants with TRE completed all study procedures including longitudinal pre-/on-CBD rs-fMRI (8M/14F, mean age = 36.2 ± 15.9 years, TRE duration = 18.3 ± 12.6 years); there were no differences in age (p = 0.99) or sex (p = 0.15) between groups. Assessments collected included seizure frequency (SF), Chalfont Seizure Severity Scale (CSSS), Columbia Suicide Severity Rating Scale (C-SSRS), Adverse Events Profile (AEP), and Profile of Mood States (POMS). Twenty-three healthy controls (HCs) received rs-fMRI and POMS once.

RESULTS

Participants with TRE showed average decrease of 71.7% in SF (p < 0.0001) and improved CSSS, AEP, and POMS confusion, depression, and fatigue subscores (all p < 0.05) on-CBD with POMS scores becoming similar to those of HCs. Paired t-tests showed significant pre-/on-CBD changes in rs-FC in cerebellum, frontal areas, temporal areas, hippocampus, and amygdala with some of them correlating with improvement in behavioral measures. Significant differences in rs-FC between pre-CBD and HCs were found in cerebellum, frontal, and occipital regions. After controlling for changes in SF with CBD, these differences were no longer present when comparing on-CBD to HCs.

SIGNIFICANCE

This study indicates that highly purified CBD modulates and potentially normalizes rs-FC in the epileptic brain. This effect may underlie its efficacy. This study provides Class III evidence for CBD's normalizing effect on rs-FC in TRE.

fMRI study of cannabidiol-induced changes in attention control in treatment-resistant epilepsy

Patients with treatment-resistant epilepsy (TRE) frequently exhibit memory and attention deficits that contribute to their poor personal and societal outcomes. We studied the effects of adjunct treatment with pharmaceutical grade cannabidiol (CBD) oral solution (Epidiolex®; Greenwich Biosciences, Inc.) on attention control processes related to stimulus conflict resolution in patients with TRE. Twenty-two patients with TRE underwent 3 T magnetic resonance imaging (MRI) before receiving (PRE) and after achieving a stable dose of CBD (ON). Functional MRI (fMRI) data were collected while patients performed 2 runs of a flanker task (FT). Patients were instructed to indicate via button press the congruent (CON) and incongruent (INC) conditions. We performed t-tests to examine with FT attention control processes at PRE and ON visits and to compare the 2 visits using derived general linear model (GLM) data (INC - CON). We performed generalized psychophysiological interaction (gPPI) analyses to assess changes in condition-based functional connectivity on FT. Median time between fMRI visits was 10 weeks, and median CBD dose at follow-up was 25 mg/kg/d. From PRE to ON, participants experienced improvements in seizure frequency (SF) (p = 0.0009), seizure severity (Chalfont Seizure Severity Scale (CSSS); p < 0.0001), and mood (Total Mood Disturbance (TMD) score from Profile of Mood States (POMS); p = 0.0026). Repeated measures analysis of variance showed nonsignificant improvements in executive function from 34.6 (23.5)% to 41.9 (22.4)% CON accuracy and from 34.2 (25.7)% to 37.6 (24.4)% INC accuracy (p = 0.199). Change in CON accuracy was associated with change in INC accuracy (r_S = 0.81, p = 0.0005). Participants exhibited CBD-induced increases in fMRI activation in the right superior frontal gyrus (SFG) and right insula/middle frontal gyrus (MFG) and decrease in activation for both regions at ON relative to PRE (corrected p = 0.05). The subset of patients who improved in FT accuracy with CBD showed a negative association between change in right insula/MFG activation and change in accuracy for the INC condition (r_S = -0.893, p = 0.0068). The gPPI analysis revealed a CBD-induced decrease in condition-based functional connectivity differences for the right SFG seed region (corrected p = 0.05). Whole-brain regression analysis documented a negative association of change in right insula/MFG condition-based connectivity with change in INC accuracy (corrected p = 0.005). Our results suggest that CBD modulates attention control processing in patients with TRE by reducing right SFG and right insula/MFG activation related to stimulus conflict resolution and by dampening differences in condition-based functional connectivity of the right SFG. Our study is the first to provide insight into how CBD affects the neural substrates involved in attention processing and how modulation of the activity and functional connectivity related to attentional control processes in the right insula/MFG may be working to improve cognitive performance in TRE.

Patient Selection for Drip and Ship Thrombolysis in Acute Ischemic Stroke

OBJECTIVES

The drip and ship model is a method used to deliver thrombolysis to acute stroke patients in facilities lacking onsite neurology coverage. We sought to determine whether our drip and ship population differs from patients treated directly at our stroke center (direct presenters).

METHODS

We retrospectively reviewed consecutive patients who received thrombolysis at an outside facility with subsequent transfer to our center between 2009 and 2011. Patients received thrombolysis after telephone consultation with a stroke specialist. We examined demographics, vascular risk factors, laboratory values, and stroke severity in drip and ship patients compared with direct presenters.

RESULTS

Ninety-six patients were identified who received thrombolysis by drip and ship compared with 212 direct presenters. The two groups did not differ with respect to sex, ethnicity, vascular risk factors, or admission glucose. The odds ratio (OR) of arriving at our hospital as a drip and ship for someone 80 years or older was 0.31 (95% confidence interval [CI] 0.15-0.61, P < 0.001). Only 21% of drip and ship patients were black versus 38% of direct presenters (OR 0.434, 95% CI 0.25-0.76, P = 0.004). Even after stratifying by age (<80 vs ≥80), a smaller proportion of drip and ship patients were black (OR 0.44, 95% CI 0.24-0.81, P = 0.008). Furthermore, we found that fewer black patients with severe strokes arrived by drip and ship (OR 0.33, 95% CI 0.11-0.98, P = 0.0028).

CONCLUSIONS

Our study showed that a smaller proportion of blacks and older adults arrived at our center by the drip and ship model. This may reflect differences in how patients are selected for thrombolysis and transfer to a higher level of care.

The Potential Impact of Maintaining a 3-Hour IV Thrombolysis Window: How Many More Patients can we Safely Treat?

BACKGROUND

In 2008, the European Cooperative Acute Stroke Study-3 (ECASS-3) demonstrated that intravenous-tissue plasminogen activator could be safely administered for acute stroke patients presenting between 3 and 4.5 hours from symptom onset. Recently, the Food and Drug Administration rejected expansion of this time window in the United States. We sought to determine how many fewer patients would be treated by maintaining this restricted time window.

METHODS

We reviewed charts from patients who received intravenous thrombolysis at the University of Alabama at Birmingham between January 2009 and December 2011. Patients were divided into two groups (treated within 3 hours of onset, treated between 3 and 4.5 hours from onset). Demographics, stroke severity and protocol deviations according to the ECASS-3 trial were collected. Our safety measures were any hemorrhagic transformation, symptomatic intracerebral hemorrhage and systemic hemorrhage.

RESULTS

Two hundred and twelve patients were identified, of whom 192 were included in our analysis. A total of 36 patients (19%) were treated between 3 and 4.5 hours. No statistical differences were seen between age (p=0.633), gender (p=0.677), race (p=0.207) or admission stroke severity (p=0.737). Protocol deviations from the ECASS-3 criteria were found in 20 patients (56%). These were primarily age > 80 and aggressive blood pressure management. Despite these deviations, we did not see significant increases in the rates of adverse events in patients treated in the extended time window.

CONCLUSIONS

Our data are consistent with previously reported international data that IV thrombolysis can safely be used up to 4.5 hours from symptom onset. Restricting the time window to 3 hours would have resulted in almost one-fifth fewer patients treated at our center.

Safety of protocol violations in acute stroke tPA administration

BACKGROUND

Intravenous (IV) tissue plasminogen activator remains the only approved therapy for acute ischemic stroke (AIS) in the United States; however, less than 10% of patients receive treatment. This is partially because of the large number of contraindications, narrow treatment window, and physician reluctance to deviate from these criteria.

METHODS

We retrospectively analyzed consecutive patients who received IV thrombolysis at our stroke center for National Institute of Neurological Disorders and Stroke (NINDS) protocol violations and rates of symptomatic intracerebral hemorrhage (sICH). Other outcome variables included systemic hemorrhage, modified Rankin Scale at discharge, and discharge disposition.

RESULTS

A total of 212 patients were identified in our stroke registry between 2009 and 2011 and included in the analysis. Protocol violations occurred in 76 patients (36%). The most common violations were thrombolysis beyond 3 hours (26%), aggressive blood pressure management (15%), elevated prothrombin time (PT) or partial thromboplastin time (PTT) (6.6%), minor or resolving deficits (4.2%), unclear time of onset (3.9%), and stroke within 3 months (3%). There were no significant differences in any of the safety outcomes or discharge disposition between patients with or without protocol violations. Controlling for age, National Institutes of Health Stroke Scale on admission, and glucose on admission, there was no significant increase in sICH (odds ratio: 3.8; 95% confidence interval: .37-38.72) in the patients who had protocol violations.

CONCLUSIONS

Despite more than one third of patients receiving thrombolysis with protocol violations, overall rates of hemorrhage remained low and did not differ from those who did not have violations. Our data support the need to expand access to thrombolysis in AIS patients.

Abstract WP72: Safety of Label- and Protocol Violations in Acute Stroke tPA Administration

Background: IV-tPA remains the only FDA approved therapy for acute ischemic stroke, however less than 10% of patients receive treatment. This is partially due to the large number of contraindications on the drug label and continued use of NINDS trial criteria for patient selection.

Methods: We retrospectively analyzed consecutive patients who received IV-tPA at our stroke center for label or NINDS protocol violations, as well as safety according to the NINDS t-PA Stroke Study definition of sICH. Other outcome variables included systemic hemorrhage, mRS at discharge and disposition.

Results: A total of 308 patients were identified in our tPA registry between 2009 and 2011. Ninety six patients were excluded because they received tPA at an outside facility prior to transfer, leaving 212 patients for analysis. Median patient age was 68 (IQR 55, 82), median pretreatment NIHSS score was 8 (IQR 5, 14). Protocol violations occurred in 103 patients (49%). The most common violations were tPA delivery beyond 3 hours (26%), aggressive blood pressure management with nicardipine (15%), elevated PT/PTT (6.6%), minor or resolving deficits (4.2%), unclear time of onset (3.9%) and stroke within 3 months (3%). Three patients had a history of ICH. There were no significant differences in any of the safety outcomes between patients with or without protocol violations (Table). Furthermore, after controlling for age, admission NIHSS and glucose, there was no significant increase in the rate of any hemorrhagic transformation (OR 1.046, p= 0.905) or sICH (OR 0.569, p= 0.613) in patients with protocol violations.

Conclusions: Despite nearly half of patients receiving tPA off label or in violation of the NINDS protocol, overall rates of hemorrhage remained low and did not differ from those who did not have violations. Our data support the need to mitigate restrictions for IV-tPA in patients presenting with acute ischemic stroke.

Abstract WP277: Aggressive Blood Pressure Management: A Perceived Contraindication to IV-tPA

Background: Our recent poll of US Primary Stroke Centers demonstrated that 23% of practitioners perceived the need for blood pressure (BP) management by means of a continuous dihydropyridine calcium channel blocker infusion (i.e. nicardipine) as a contraindication to IV-tPA. While the NINDS study originally excluded patients who required "aggressive" BP management, the Activase® label is silent on this criterion. In view of this persistent belief, we sought to examine the safety of IV tPA administered with nicardipine.

Methods: A retrospective cohort study was performed over a period of 36 months examining consecutive patients treated with IV-tPA at our comprehensive stroke center who received nicardipine vs. intermittent IV labetalol or those requiring no BP medications. Patient demographics, past medical history, and stroke severity were compared. Safety was assessed by (1) symptomatic intracerebral hemorrhage (sICH) within 36 hours, defined as parenchymal hemorrhage in combination with ≥ 4 points increase in NIHSS, and (2) the presence of any hemorrhagic transformation (HT) on repeat CT or MRI.

Results: A total of 212 patients were treated with IV-tPA, median age 68 (range 24-99), median pre-tPA bolus NIHSS 8 (range 0-32) with no differences between nicardipine treated (n=32, 15%) vs. others (n=180). Patients treated with nicardipine were more frequently female (63%; p=0.0337). Past medical history was similar except for CHF (nicardipine 0, other 15%, p=0.0087) and previous stroke (nicardipine 59%, other 36%, p=0.0132). Despite these imbalances, nicardipine patients vs. others had similar rates of sICH (0 vs. 3.3%; p=NS), or any HT (3.1% vs. 9.5%; p=NS). No telephone-assisted tPA drip-n-ship patients (n=96) received nicardipine prior to or during tPA infusion due to non-formulary status at transferring hospitals; sICH rate in this group was 4% vs. 2% (p=NS) in non-transfers with or without nicardipine.

Conclusions: IV thrombolysis in patients requiring continuous nicardipine infusion is safe compared to those requiring less intensive BP management. The need for continuous nicardipine infusion should not be construed as rationale for withholding IV tPA in acute ischemic stroke patients.

Abstract TP278: Prevalence Of Systemic Inflammatory Response Syndrome and its Impact On Outcome In Acute Ischemic Stroke Patients Receiving IV tPA Therapy

Background: Systemic Inflammatory Response Syndrome (SIRS) is a generalized inflammatory state linked to a release of various pro- and anti-inflammatory cytokines and associated with fibrin deposition, platelet aggregation, and coagulopathies. Although SIRS is associated with various inflammatory and ischemic conditions, its prevalence and impact on patients with acute ischemic stroke (AIS) has not been extensively studied.

Methods: A retrospective cross sectional study was used to look at the prevalence of SIRS and its impact on outcome in AIS patients treated with IV tPA between 2009-2011 at our tertiary care center. SIRS was diagnosed if two or more of the following were present: temperature < 36°C or > 38°C, heart rate > 90/min, respiratory rate >20/min or PaCO 2 <32 mmHg and WBC count <4000/mm 3 or >12000/mm 3 or 10% bands. Patients meeting the SIRS criteria for at least 24h were included in the study. Patients with signs of active infection such as pneumonia, UTI, bacteremia, and sinusitis or deep venous thrombosis were excluded from the study. The discharge modified Rankin score (mRS) was used to compare the short-term outcomes between patients with and without SIRS. An mRS of 4-6 was used to define poor functional outcome.

Results: Out of the 212 patients screened, 44 met the SIRS criteria (21%). The median NIHSS for SIRS patients was 9 (range 0-32). SIRS patients were more likely to have a longer length of stay than non-SIRS patients (5 vs. 3 days; p<0.0001). Patients with SIRS had worse functional outcomes compared to patients without SIRS (OR=2.824, 95% CI, 1.358 - 5.871, p=0.0054). Adjusting for pre-tPA NIHSS, age and race, SIRS remained a predictor of poor outcome (OR= 2.581, 95% CI, 1.163 - 5.727, p=0.0197). Presence of SIRS did not have a significant effect upon in-hospital mortality (OR=1.978, 95% CI, 0.774 - 5.057, p=0.1545).

Conclusions: One out of five AIS patients treated with IV tPA developed SIRS. The presence of SIRS is associated with poor short-term functional outcomes and prolonged length of stay.

Abstract WP129: The Potential Impact of Maintaining a 3-Hour IV tPA Window

Background: In 2008, the ECASS-3 trial demonstrated that IV-tPA could be safely administered for acute stroke patients presenting between 3 and 4.5 hours from symptom onset. Recently, the FDA rejected expansion of the 3 hour time window. We sought to determine the safety of the ECASS protocol at our center and assess how many fewer patients would be treated by restricting treatment to 3 hours.

Methods: We reviewed charts from patients who received IV tPA at our comprehensive stroke center and excluded patients who were drip and ship. Patients were divided into two groups (receiving tPA within 3 hours of onset, receiving tPA between 3 and 4.5 hours from onset). Demographics, admission NIHSS and protocol deviations (NINDS and ECASS-3) were collected. Safety was assessed using any hemorrhagic transformation (MRI or CT), symptomatic ICH and systemic hemorrhage.

Results: Two hundred and twelve patients were identified in our tPA registry between 2009 and 2011, of whom 36 received tPA between 3 and 4.5 hours. No statistical differences were seen between age (p=0.633), gender (p=0.677), race (p=0.207) or admission NIHSS (0.737). Protocol deviations from the ECASS 3 criteria were found in 20 patients (56%). The most common deviations were age > 80 (8/36, 22%) and aggressive blood pressure management (5/20, 25%). Safety outcomes were not different between the two groups (Table).

Conclusions: Our data are consistent with previously reported international data that IV thrombolysis can safely be used up to 4.5 hours from symptom onset. By expanding the three hour time window, we were able to treat an additional 17% over three years at our stroke center without an increase in adverse outcomes. Physicians should not withhold thrombolytic therapy based solely on a three hour time window as this unnecessarily restricts the population of patients who could potentially benefit from treatment.

Abstract WMP78: Investigating the Utility of Previously Developed Prediction Scores in AIS patients in the Stroke Belt

Background: A number of scoring systems have been developed in different geographic and treatment populations, however, it remains unknown how these scores perform in the Stroke Belt population. We sought to validate and assess the utility of the SEDAN, THRIVE, HIAT and HIAT2 scoring systems among patients receiving systemic (IV tPA) and endovascular (IAT) reperfusion.

Methods: We retrospectively reviewed all IV tPA and IAT patients presenting to our tertiary care center from 2009-2011. The scores were assessed in IV tPA only patients, IAT only patients and in patients who received both therapies (IV-IA). We tested THRIVE for predicting mRS 3-6, HIAT and HIAT2 for mRS 4-6, and SEDAN for symptomatic intracerebral hemorrhage (sICH). sICH was defined as a Type 2 parenchymal hemorrhage with deterioration in NIHSS score of 4 points or death. ROC curves were used to evaluate each score within the three groups.

Result: Of the 366 patients who were included in this study, 89 had IAT only, 243 had IV tPA only and 34 had IV-IA. Figure 1a shows their demographic and baseline characteristics. Figure 1b shows the performance of SEDAN, THRIVE, HIAT and HIAT2 scores in our population (ROC range from 0.512-0.818).

Conclusion: The two scores developed in the Stroke Belt, HIAT and HIAT2, performed well in the patient group for which they were developed (IAT). Additionally, they are also good predictors in other groups (IV and IV-IA). THRIVE performed well for predicting mRS 3-6 in all three groups. SEDAN was only moderately useful in predicting sICH after IV tPA. SEDAN had poor predictive value in IAT and IV-IA. These results highlight the need for validating clinical scores in different patient populations to determine their generalizability to all stroke patients.

Absence of DAZ gene mutations in cases of non-obstructed azoospermia

Sequenced-tagged site (STS) analysis of the Y chromosome long arm (Yq) of azoospermic males has identified a minimum common deleted region of several hundred kilobases in approximately 13% of cases. A candidate azoospermia gene, DAZ (deleted in azoospermia), has been isolated from this region. DAZ has also been shown to be absent in severely oligozoospermic males albeit at a much lower frequency. These data, although highly suggestive, do not constitute formal proof that DAZ actually plays a role in azoospermia, as no small intragenic deletions, rearrangements or point mutations in the gene have been found. In this study we report the screening of DNA from 168 azoospermic/oligospermic males for the presence of the DAZ gene. Deletions involving DAZ were detected in five out of 43 (11.6%) azoospermic males whereas none were found in the remaining 125 oligospermic patients. We present the genomic structure of the 5' end of the DAZ gene together with its sequence analysis in 30 non-obstructed azoospermic males. No mutations in DAZ were found in any of the patients sequenced. These data provide no formal proof that DAZ is AZF. Thus the possibility is still valid that another gene(s) mapping to the deletion interval may be responsible for, or contribute to, the observed phenotypes. Alternatively, if DAZ is AZF, they suggest that the most frequent cause of gene inactivation is via large deletions possibly mobilized by Y chromosome repetitive sequences.