Emanuel Syndrome

Synonym: Supernumerary der(22)t(11;22) Syndrome

Emanuel BS, Zackai EH, Medne L.

Publication Details


Clinical characteristics.

Emanuel syndrome is characterized by severe intellectual disability, microcephaly, failure to thrive, preauricular tags or pits, ear anomalies, cleft or high-arched palate, micrognathia, kidney abnormalities, congenital heart defects, and genital abnormalities in males.


Emanuel syndrome is caused by a chromosome imbalance consisting of either of the following:

  • A derivative chromosome 22 [der(22)] as a supernumerary chromosome with the following karyotype:
    • 47,XX,+der(22)t(11;22)(q23;q11) in females
    • 47,XY,+der(22)t(11;22)(q23;q11) in males
  • Rarely, a balanced (11;22) translocation as well as the supernumerary derivative chromosome

The supernumerary der(22) chromosome is easily identified by routine G-band analysis at the 500-550 band level.


Treatment of manifestations: Care by a multidisciplinary team is usually necessary; standard management of gastroesophageal reflux, anal atresia (or stenosis), inguinal hernias, cardiac defects, cleft palate, hip dysplasia, other skeletal complications, hearing loss, cryptorchidism and/or micropenis, refractive errors, and strabismus or other ophthalmologic issues; ongoing physical, occupational, and speech therapies; alternative communication methods to facilitate communication.

Prevention of secondary complications: Attention to the airway during sedation and/or operative procedures in an institution with pediatric anesthesiologists.

Surveillance: Follow up as needed based on the extent of systemic involvement in each individual case; regular developmental assessments; periodic reevaluation by a medical geneticist.

Genetic counseling.

In more than 99% of cases, one of the parents of a proband with Emanuel syndrome is a balanced carrier of a t(11;22)(q23;q11.2) and is phenotypically normal. In most cases, a carrier parent has inherited the t(11;22) from one of his or her parents. When one of the parents of a proband is a carrier of the balanced t(11;22) possible outcomes of future pregnancies of the parents include: normal chromosomes, supernumerary der(22) syndrome, balanced t(11;22) carrier, and spontaneous abortion as a result of supernumerary der(22) or another meiotic malsegregant. Risks vary depending on whether the mother or father of a proband is the balanced translocation carrier. Prenatal diagnosis for pregnancies at increased risk is possible if the chromosome abnormality has been confirmed in the family.


Clinical Diagnosis

Emanuel syndrome is characterized by:

  • A distinct phenotype consisting of the following [Fraccaro et al 1980, Zackai & Emanuel 1980, Lin et al 1986, Carter et al 2009]:
    • Severe intellectual disability
    • Microcephaly
    • Failure to thrive
    • Preauricular tag or pit
    • Ear anomalies
    • Cleft or high-arched palate
    • Micrognathia
    • Kidney abnormalities
    • Congenital heart defects
    • Genital abnormalities in males
  • A chromosomal imbalance consisting of either of the following (see Figure 1):
    • Most commonly, a derivative chromosome 22[der(22)] (Figure 1A) as a supernumerary chromosome with the following karyotype:
      • 47,XX,+der(22)t(11;22)(q23;q11) in females
      • 47,XY,+der(22)t(11;22)(q23;q11) in males
    • Rarely, a balanced (11;22) translocation as well as the supernumerary derivative chromosome. Figure 1B shows a karyotype of a balanced t(11;22) carrier.
Figure 1 . A.

Figure 1

A. Karyotype and schematic ideogram showing the supernumerary derivative chromosome 22, which results in trisomy of chromosome 11q23-qter and 22q cen-q11 B. Karyotype and schematic ideogram showing a balanced translocation carrier.

Affected individuals are usually identified in the newborn period as the offspring of balanced (11;22) translocation carriers. The progeny affected with Emanuel syndrome are genotypically unbalanced because the der(22) is a supernumerary chromosome.


Cytogenetic testing. When a chromosomal abnormality is suspected, routine cytogenetic analysis is recommended. The supernumerary der(22) chromosome is easily identified by routine G-band analysis at the 500-550 band level in individuals with the disorder.

  • Parental karyotypes should be performed to determine whether one parent is a carrier of the balanced translocation, t(11;22).
  • In the rare instance in which one of the parents is not a balanced translocation carrier, commercially available FISH probes for the 22q11.2 deletion and for the telomere of 11q can identify the supernumerary chromosome in the karyotype as being derived from chromosomes 11 and 22. Chromosomal microarray analysis can also be employed to verify the composition of the supernumerary chromosome.

    Note: Chromosomal microarray cannot currently detect balanced translocations, in which there is no net gain or loss of genetic material.

The combined use of these testing modalities identifies 100% of the small acrocentric chromosomes resulting in Emanuel syndrome.

Molecular Genetic Testing

Genes. Duplication of genes on the supernumerary derivative chromosome 22 is the only genetic defect known to be associated with Emanuel syndrome. The clinical phenotype arises from duplication of 22q10-22q11 and duplication of 11q23-qter on the supernumerary der(22).

Note: Duplication of the short (p) arm of chromosome 22 is clinically insignificant, as chromosome 22 is an acrocentric chromosome with the p arm containing heterochromatin.

Clinical testing

Table 1.

Table 1.

Summary of Molecular Genetic Testing Used in Emanuel Syndrome

Testing Strategy

To confirm/establish the diagnosis in a proband. When supernumerary der(22) is suspected, perform routine cytogenetic analysis since the additional chromosome is easily identified as an additional small acrocentric chromosome.

  • Use of chromosomal microarray analysis will confirm the duplication of proximal 22q and distal 11q.

    Note: If chromosomal microarray is done prior to karyotype and duplication of proximal 22q with duplication of distal 11q is detected, a limited karyotype should be pursued to confirm that the duplications are due to a supernumerary chromosome.


  • Use of FISH probes for 22q can determine that the extra chromosome is partially derived from chromosome 22.
  • Use of FISH probes for the 11q telomere can confirm that the translocation is between 11q and 22q.

Clinical Characteristics

Clinical Description

Well over 100 individuals with supernumerary der(22) have been reported [Fraccaro et al 1980, Zackai & Emanuel 1980, Lin et al 1986]. Significant mortality is associated with life-threatening congenital malformations such as congenital heart defects, diaphragmatic hernia, or renal insufficiency. The highest mortality rate is in the first months of life. With improved palliative care and time, survival chances improve and survival into adulthood has been well documented.

Affected children are usually identified in the newborn period as the offspring of balanced (11;22) translocation carriers.

Constitutional. Most individuals have pre- and postnatal growth retardation and associated dysmorphic features.

Craniofacial. Observed dysmorphic features include micro-brachycephaly, prominent forehead, epicanthus, downslanted palpebral fissures, wide and depressed nasal bridge, long and deep philtrum, microretrognathia, and abnormal auricles (ranging from microtia to large ears) often associated with preauricular ear pits and/or tags (see Figure 2).

Figure 2. . Four individuals with Emanuel syndrome.

Figure 2.

Four individuals with Emanuel syndrome. Note the round face, deeply set, round eyes, and prominent forehead in children A (age ~6 months) and B (age 3 years). Note the coarsening of facial features over time in individual D; photos are taken at age one (more...)

Cardiac. Congenital heart defects, seen in approximately 60% of individuals with supernumerary der(22), contribute to morbidity and mortality. Heart defects include atrial septal defect (ASD), ventricular septal defect, tetralogy of Fallot, truncus arteriosus, tricuspid atresia, coarctation of the aorta, aberrant subclavian artery, persistent left superior vena cava, and patent ductus arteriosus.

Genitourinary. Renal malformations, seen in approximately 30% of affected individuals, range from complete renal agenesis to various degrees of renal hypoplasia. Males often have cryptorchidism, small scrotum, and micropenis. Uterine malformations can occasionally be observed in females.

Gastrointestinal. Diaphragmatic hernia and hypoplasia or eventration of the diaphragm have been observed.

Anal atresia with or without fistula is seen in about 20% of affected individuals. Anal stenosis without complete atresia is observed as well.

Inguinal hernias are uncommon but well documented.

Biliary atresia, Hirschsprung disease, abnormal liver lobation, extrahepatic biliary ducts, absent gallbladder, and polysplenia have been observed occasionally.

Poor weight gain is common. While specific feeding problems are often not described, gastroesophageal reflux and difficulties with suck and swallow are common.

Musculoskeletal. All affected individuals have significant centrally based hypotonia.

Curvature of the spine is most likely a secondary complication of severe hypotonia and resulting motor delays.

Congenital hip dislocation or subluxation is common.

Arachnodactyly and tapering fingers are characteristic.

Club foot and joint contractures can be congenital or develop later in life.

Other, less frequently observed skeletal malformations include 13 pairs of ribs, hypoplastic clavicles, cubitus valgus, radio-ulnar synostosis, and 4-5 syndactyly of the toes. Lumbar myelomeningocele has been reported once . Sacral dimple is common.

Delayed bone age is mentioned in a few case reports.

Palate. Cleft palate is seen in approximately 50% of affected individuals.

Eyes. Most persons with Emanuel syndrome have normal vision. Although uncommon, eye abnormalities have included strabismus and myopia. Ptosis and degenerative retinal changes are rarer.

Ears, nose, and throat. The external ear auricle is typically malformed and preauricular ear pits and/or tags are characteristic. Severe microtia with atresia of the external auditory canal and deafness have been reported. Hearing loss is uncommon, but milder forms may be underestimated because of the difficulties associated with accurate hearing evaluation in individuals with severe developmental delay.

Angular mouth pits or clefts, cleft maxilla, laryngomalacia, and branchial sinuses have been reported. Bifid uvula is also associated.

CNS. Microcephaly is present in all affected individuals.

The incidence of structural brain abnormalities is not known as brain imaging is not required to establish the diagnosis. Reported malformations have included Dandy-Walker malformation, agenesis of the corpus callosum, arrhinencephaly, and absent olfactory bulbs and tracts.

Seizures are reported in a few affected individuals and abnormal EEGs without clinical seizures in another small subset.

Development. All children with Emanuel syndrome have severe global developmental delays. Adults function in the spectrum of severe-to-profound intellectual disability. Most individuals can sit unsupported. Walking is often difficult because of poor motor coordination; only a small number learn to walk. Speech and language development is significantly delayed. Receptive language is better than expressive language and some individuals are able to use single words to communicate.

Other findings include congenital immunoglobulin deficiency, thymic-dependent immunodeficiency, and dysplastic teeth.

Genotype-Phenotype Correlations

All individuals with Emanuel syndrome have the supernumerary der(22), which results from almost identical breakpoints on both 11q23 and 22q11. The breakpoints differ by only a few nucleotides [Shaikh et al 1999, Kurahashi et al 2000a, Kurahashi & Emanuel 2001]. Genotype-phenotype correlation, however, is difficult as the clinical findings result from duplicated genetic material. While systemic involvement can vary, developmental outcome is uniformly in the spectrum of severe-to-profound intellectual disability.


Penetrance is complete in individuals with the supernumerary der(22).


Anticipation is not associated with the supernumerary der(22).


Supernumerary der(22) syndrome almost always results from 3:1 malsegregation of a balanced t(11;22) in an unaffected parent [Shaikh et al 1999].

Older case reports published prior to G banding described this chromosome abnormality as "partial trisomy 22" or "partial trisomy 11."

In 2004, supernumerary der(22) syndrome was named Emanuel syndrome.


Supernumerary der(22) is a rare chromosomal disorder; its prevalence is unknown.

The prevalence of balanced t(11;22) carriers is unknown in the general population.

Differential Diagnosis

Clinical features that overlap with Emanuel syndrome can be seen in the syndromes listed below. Chromosome analysis always confirms the diagnosis of Emanuel syndrome and rules out other diagnoses.


Evaluations Following Initial Diagnosis

No current guidelines to evaluate the clinical manifestations that contribute to morbidity and mortality have been published. The following recommendations to establish the extent of disease and needs in an individual diagnosed with Emanuel syndrome are based on the literature and the authors' experience:

  • Cardiac evaluation with an echocardiogram to screen for cardiac defects. ASDs (atrial septal defects) are the most common defects and may not be detected by auscultation alone.
  • Renal ultrasound examination to evaluate for structural kidney anomalies; if indicated, vesicoureterogram (VCUG) to evaluate for vesicoureteral reflux
  • Palatal evaluation for cleft palate
  • Gastrointestinal evaluation with appropriate radiologic studies for structural anomalies of the gastrointestinal (GI) tract, in particular anal stenosis or diaphragmatic abnormalities, gastroesophageal reflux
  • Feeding and swallowing assessment
  • Orthopedic evaluation with appropriate radiologic studies for hip dysplasia as well as joint contractures, club foot, curvature of the spine, and radio-ulnar synostosis
  • Otolaryngology (ENT) evaluation for stenosis or atresia of ear canals
  • Audiology evaluation with auditory brain stem response testing and otoacoustic emission testing (See Hereditary Hearing Loss and Deafness for more information about this testing.)
  • Ophthalmologic evaluation, including dilated fundoscopic examination, to assess visual acuity and to evaluate for strabismus
  • Urologic evaluation in males with cryptorchidism and/or micropenis
  • Evaluation by a developmental pediatrician and therapists to develop educational/therapeutic intervention with emphasis on communication skills
  • Medical genetics evaluation for genetic counseling and to identify at-risk relatives (The +der(22) is almost always inherited from a carrier parent.)

Treatment of Manifestations

Depending on the age and extent of systemic involvement of the individual with Emanuel syndrome, evaluations involving healthcare providers from multiple specialties are necessary.

In some cases, palliative care is appropriate when there are severe structural defects and/or renal failure.

  • Standard management of gastroesophageal reflux; supplementary formulas and consideration of enteral feeds if there is failure to thrive
  • Surgical correction for anal atresia (or stenosis if indicated) and inguinal hernias
  • Standard interventions for:
    • Cardiac defects
    • Cleft palate
    • Hip dysplasia and other skeletal complications; assistive devices such as walkers are often required for ambulation
    • Hearing loss
    • Cryptorchidism and/or micropenis
    • Refractive errors, strabismus, or other ophthalmologic issues
    • Seizures, if present
  • Ongoing physical, occupational, and speech therapies to optimize developmental outcome
  • Alternative communication methods to facilitate communication as verbal skills are often very limited

Prevention of Secondary Complications

Care during sedation and/or operative procedures should be provided by a pediatric anesthesiologist as small airways, various palatal abnormalities, and laryngomalacia can be seen in children with Emanuel syndrome.


The following are appropriate:

  • Follow up as needed based on the extent of systemic involvement in the affected individual
  • Regular assessment of developmental progress to guide therapeutic interventions and educational modalities
  • Periodic reevaluation by a medical geneticist to apprise the family of new developments and/or recommendations

Evaluation of Relatives at Risk

See Genetic Counseling for issues related to testing of at-risk relatives for genetic counseling purposes.

Therapies Under Investigation

Search ClinicalTrials.gov for access to information on clinical studies for a wide range of diseases and conditions. Note: There may not be clinical trials for this disorder.


Patients and their families should be informed regarding natural history, treatment, mode of inheritance, genetic risks to other family members, and consumer-oriented resources.

Genetic Counseling

Genetic counseling is the process of providing individuals and families with information on the nature, inheritance, and implications of genetic disorders to help them make informed medical and personal decisions. The following section deals with genetic risk assessment and the use of family history and genetic testing to clarify genetic status for family members. This section is not meant to address all personal, cultural, or ethical issues that individuals may face or to substitute for consultation with a genetics professional. —ED.

Mode of Inheritance

Emanuel syndrome is an inherited chromosome abnormality. It is the result of 3:1 meiotic segregation of the balanced translocation t(11;22)(q23;q11). This rearrangement is the only known recurrent, non-Robertsonian translocation in humans.

Risk to Family Members

Parents of a proband

  • In greater than 99% of cases, one of the parents of a proband with Emanuel syndrome is a balanced carrier of a t(11;22)(q23;q11.2) and is phenotypically normal. There is a single case report of supernumerary der(22) arising from de novo (11;22) translocation in the paternal germline with probable unbalanced adjacent 1 segregation and maternal non-disjunction of chromosome 22 in meiosis I.
  • Parents of a proband with Emanuel syndrome should be offered chromosome analysis.
  • Statistically, the mother of a proband with supernumerary der(22) is more likely than the father to be a carrier of the balanced t(11;22).
  • In most cases, a carrier parent has inherited the t(11;22) from one of his or her parents.

Sibs of a proband

  • Sibs of a proband who have no findings of Emanuel syndrome:
    • Are not at risk for Emanuel syndrome;
    • Have almost no chance of having a different unbalanced chromosome abnormality;
    • Have an estimated 50% chance of having a balanced translocation;
    • Have an estimated 50% chance of having normal chromosomes.
  • Sibs of a proband who have findings of Emanuel syndrome (e.g., severe developmental delays, poor growth, and multiple congenital anomalies) almost always have supernumerary der(22).
  • When one of the parents of a proband is a carrier of the balanced t(11;22), possible outcomes of future pregnancies of the parents include the following:
    • Normal chromosomes
    • Supernumerary der(22) syndrome
    • Balanced t(11;22) carrier
    • Spontaneous abortion with supernumerary der(22) or another meiotic malsegregant
  • In any given pregnancy, the exact chance of each of the above four pregnancy outcomes occurring is not known. Furthermore, risks vary depending on whether the mother or father of a proband is the balanced translocation carrier [Fraccaro et al 1980, Zackai & Emanuel 1980]:
    • The risk of having a liveborn infant with supernumerary der(22) is higher if the mother carries a balanced t(11;22) than if the father carries a balanced t(11;22).
    • The overall risk of having a liveborn infant with supernumerary der(22) when a parent carries a balanced t(11;22) is estimated to be between 1.8% and 5.6%.
    • The overall risk of having a spontaneous abortion with supernumerary der(22) or another meiotic malsegregant when a parent carries a balanced t(11;22) is estimated to be between 23% and 37%.

Offspring of a proband. Individuals with Emanuel syndrome are unlikely to reproduce because of severe cognitive impairment.

Other family members of a proband

  • The risk to other family members depends on the status of the proband's parents.
  • Family members of the parent carrying the balanced t(11;22) are at risk of being carriers or having Emanuel syndrome. For those identified as carriers, the risk would be the same as described above for parents who carry a balanced t(11;22).
  • Chromosome analysis should be offered to at-risk family members.

Carrier Detection

At-risk family members can be tested by chromosome analysis. Carrier testing is not routinely performed in at-risk family members when they are minors, but rather when they are adults and can understand the reproductive implications of being a balanced translocation carrier.

Unaffected siblings are typically tested for carrier status when they are legal adults, of reproductive age and able to understand the reproductive implications of being a carrier.

Related Genetic Counseling Issues

Family planning

  • The optimal time for determination of genetic risk and discussion of the availability of prenatal testing is before pregnancy.
  • It is appropriate to offer genetic counseling (including discussion of potential risks to offspring and reproductive options) to young adults who are or are at risk of being balanced translocation carriers.

Prenatal Testing

Accurate interpretation of prenatal testing results for at-risk pregnancies requires prior identification of the translocation in a family member.

Prenatal diagnosis for pregnancies at increased risk is possible by chromosome analysis of fetal cells obtained by chorionic villus sampling (CVS) at approximately ten to 12 weeks' gestation or amniocentesis usually performed at approximately 15 to 18 weeks' gestation. The two methods of obtaining tissue for testing are equally sensitive in detecting the supernumerary der(22).

Note: Gestational age is expressed as menstrual weeks calculated either from the first day of the last normal menstrual period or by ultrasound measurements.

Preimplantation genetic diagnosis (PGD), which has been successfully performed on several occasions [Van Assche et al 1999], may be an option for some families at increased risk.


GeneReviews staff has selected the following disease-specific and/or umbrella support organizations and/or registries for the benefit of individuals with this disorder and their families. GeneReviews is not responsible for the information provided by other organizations. For information on selection criteria, click here.

  • Chromosome 22 Central
    c/o Murney Rinholm
    7108 Partinwood Drive
    Fuquay-Varina NC 27526
    Phone: 919-567-8167
    Email: usinfo@c22c.org
  • Chromosome 22 Central

Molecular Genetics

Information in the Molecular Genetics and OMIM tables may differ from that elsewhere in the GeneReview: tables may contain more recent information. —ED.

Table B.

Table B.

OMIM Entries for Emanuel Syndrome (View All in OMIM)

Molecular Genetic Pathogenesis

Molecular genetic pathogenesis is not known as Emanuel syndrome results from duplicated genomic segments of chromosomes 11q and 22q, which include a significant number of genes.


Literature Cited

  • Carter MT, Barrowman NJ, St Pierre SA, Emanuel BS, Boycott KM. Risk of breast cancer not increased in translocation 11;22 carriers: analysis of 80 pedigrees. Am J Med Genet A. 2010;152A:212–4. [PMC free article: PMC2802109] [PubMed: 20034094]

  • Carter MT, St Pierre SA, Zackai EH, Emanuel BS, Boycott KM. Phenotypic delineation of Emanuel syndrome (supernumerary derivative 22 syndrome): Clinical features of 63 individuals. Am J Med Genet A. 2009;149A:1712–21. [PMC free article: PMC2733334] [PubMed: 19606488]

  • Doyen J, Carpentier X, Haudebourg J, Hoch B, Karmous-Benailly H, Ambrosetti D, Fabas T, Amiel J, Lambert JC, Pedeutour F. Renal cell carcinoma and a constitutional t(11;22)(q23;q11.2): case report and review of the potential link between the constitutional t(11;22) and cancer. Cancer Genet. 2012;205:603–7. [PubMed: 23117075]

  • Fraccaro M, Lindsten J, Ford CE, Iselius L. The 11q;22q translocation: a European collaborative analysis of 43 cases. Hum Genet. 1980;56:21–51. [PubMed: 7203479]

  • Jobanputra V, Chung WK, Hacker AM, Emanuel BS, Warburton D. A unique case of der(11)t(11;22),-22 arising from 3:1 segregation of a maternal t(11;22) in a family with co-segregation of the translocation and breast cancer. Prenat Diagn. 2005;25:683–6. [PMC free article: PMC2810961] [PubMed: 16049998]

  • Kurahashi H, Emanuel BS. Long AT-rich palindromes and the constitutional t(11;22) breakpoint. Hum Mol Genet. 2001;10:2605–17. [PubMed: 11726547]

  • Kurahashi H, Shaikh TH, Hu P, Roe BA, Emanuel BS, Budarf ML. Regions of genomic instability on 22q11 and 11q23 as the etiology for the recurrent constitutional t(11;22). Hum Mol Genet. 2000a;9:1665–70. [PubMed: 10861293]

  • Kurahashi H, Shaikh TH, Zackai EH, Celle L, Driscoll DA, Budarf ML, Emanuel BS. Tightly clustered 11q23 and 22q11 breakpoints permit PCR-based detection of the recurrent constitutional t(11;22). Am J Hum Genet. 2000b;67:763–8. [PMC free article: PMC1287537] [PubMed: 10903930]

  • Lin AE, Bernar J, Chin AJ, Sparkes RS, Emanuel BS, Zackai EH. Congenital heart disease in supernumerary der(22),t(11;22) syndrome. Clin Genet. 1986;29:269–75. [PubMed: 3720005]

  • Lindblom A, Sandelin K, Iselius L, Dumanski J, White I, Nordenskjold M, Larsson C. Predisposition for breast cancer in carriers of constitutional translocation 11q;22q. Am J Hum Genet. 1994;54:871–6. [PMC free article: PMC1918254] [PubMed: 8178827]

  • Shaikh TH, Budarf ML, Celle L, Zackai EH, Emanuel BS. Clustered 11q23 and 22q11 breakpoints and 3:1 meiotic malsegregation in multiple unrelated t(11;22) families. Am J Hum Genet. 1999;65:1595–607. [PMC free article: PMC1288370] [PubMed: 10577913]

  • Van Assche E, Staessen C, Vegetti W, Bonduelle M, Vandervorst M, Van Steirteghem A, Liebaers I. Preimplantation genetic diagnosis and sperm analysis by fluorescence in-situ hybridization for the most common reciprocal translocation t(11;22). Mol Hum Reprod. 1999;5:682–90. [PubMed: 10381825]

  • Wieland I, Muschke P, Volleth M, Ropke A, Pelz AF, Stumm M, Wieacker P. High incidence of familial breast cancer segregates with constitutional t(11;22)(q23;q11). Genes Chromosomes Cancer. 2006;45:945–9. [PubMed: 16845657]

  • Zackai EH, Emanuel BS. Site-specific reciprocal translocation, t(11;22) (q23;q11), in several unrelated families with 3:1 meiotic disjunction. Am J Med Genet. 1980;7:507–21. [PubMed: 7211960]

Chapter Notes

Author Notes

Web: humangenetics.chop.edu


We would like to thank Stephanie St Pierre, all the families and Chromosome 22 Central for their support of our research efforts.

Revision History

  • 5 February 2015 (me) Comprehensive update posted live
  • 11 May 2010 (me) Comprehensive update posted live
  • 20 April 2007 (me) Review posted to live Web site
  • 8 January 2007 (bse) Original submission