Incomplete trisomy 22. III. Mosaic-trisomy 22 and the problem of full trisomy 22

Trisomy 22 Mosaicism from Prenatal to Postnatal Findings: A Case Series and Systematic Review of the Literature

BACKGROUND

Among aneuploidies compatible with life, trisomy 22 mosaicism is extremely rare, and only about 25 postnatal and 18 prenatal cases have been described in the literature so far. The condition is mainly characterized by facial and body asymmetry, cardiac heart defects, facial dysmorphisms, growth failure, delayed puberty, and variable degrees of neurodevelopmental delay.

PROBLEM

The scattered information regarding the condition and the dearth of data on its natural history and developmental outcomes restrict genetic counseling, particularly in prenatal settings. Moreover, a prompt diagnosis is frequently delayed by the negative selection of trisomic cells in blood, with mosaicism percentage varying among tissues, which often entails the need for further testing. Purpose/topic: The aim of our work is to provide assistance in prenatal and postnatal genetic counseling by systematically delineating the current knowledge of the condition. This entails defining the prenatal and postnatal characteristics of the condition and presenting novel data from three cases, both prenatally and postnatally. Additionally, we report the developmental outcomes observed in two new patients.

Mosaic trisomy 22 at amniocentesis: Prenatal diagnosis and literature review

OBJECTIVE

We present prenatal diagnosis of mosaic trisomy 22 at amniocentesis in a pregnancy with facial cleft, oligohydramnios and intrauterine growth restriction (IUGR), and we review the literature.

CASE REPORT

A 37-year-old woman underwent amniocentesis at 19 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 47,XX,+22[9]/46,XX[9]. Array comparative genomic hybridization (aCGH) analysis on uncultured amniocytes showed a result of arr(22) × 3 [0.8]. Prenatal ultrasound revealed fetal median facial cleft, oligohydramnios and IUGR. Repeat amniocentesis at 22 weeks of gestation using uncultured amniocytes revealed an aCGH result of arr 22q11.1q13.33 (17,397,498-51,178,264) × 2.8 compatible with 80% mosaicism for trisomy 22, and a fluorescence in situ hybridization (FISH) result of mosaic trisomy 22 with trisomy 22 in 54/100 interphase cells. The cultured amniocytes at repeat amniocentesis had a karyotype of 47,XX,+22[12]/46,XX[8]. The parental karyotypes were normal. Polymorphic DNA marker analysis confirmed a maternal origin of the extra chromosome 22. The pregnancy was terminated, and a 256-g female fetus was delivered with facial dysmorphism and median facial cleft. Cytogenetic analysis of the skin fibroblasts revealed a karyotype of 47,XX,+22[33]/46,XX[7].

CONCLUSION

Fetuses with high level mosaicism for trisomy 22 at amniocentesis may present IUGR, facial cleft and oligohydramnios on prenatal ultrasound.

Live-born trisomy 22: patient report and review

Trisomy 22 is a common trisomy in spontaneous abortions. In contrast, live-born trisomy 22 is rarely seen due to severe organ malformations associated with this condition. Here, we report on a male infant with complete, non-mosaic trisomy 22 born at 35 + 5 weeks via caesarean section. Peripheral blood lymphocytes and fibroblasts showed an additional chromosome 22 in all metaphases analyzed (47,XY,+22). In addition, array CGH confirmed complete trisomy 22. The patient's clinical features included dolichocephalus, hypertelorism, flattened nasal bridge, dysplastic ears with preauricular sinuses and tags, medial cleft palate, anal atresia, and coronary hypospadias with scrotum bipartitum. Essential treatment was implemented in close coordination with the parents. The child died 29 days after birth due to respiratory insufficiency and deterioration of renal function. Our patient's history complements other reports illustrating that children with complete trisomy 22 may survive until birth and beyond.

Prenatal diagnosis and postnatal follow-up of a child with mosaic trisomy 22 with several levels of mosaicism in different tissues

We report on the case of a patient with mosaic trisomy 22, who was diagnosed prenatally by amniocentesis during the 16(th) week of pregnancy. In the foetus, three trisomic clones were found out of the nine that were analyzed (the other six clones had a 46,XY karyotype). Cytogenetic analysis of cord blood during the 20(th) week of pregnancy showed a normal male karyotype; however, a placental biopsy that was performed at the same time showed 100% and 95% trisomic cells in the chromosomal analysis of direct and long-term cultures, respectively. A follow-up ultrasonographic examination excluded major congenital malformations and the abdominal and cranial circumferences were normal until the 24(th) week of pregnancy. At this point, a deflection of the growth curve occurred and the values were persistently below the 3(rd) centile until birth. After birth, karyotypic and fluorescent in situ hybridisation analyses performed on the fibroblasts of the neonate showed that 3-4% of the cell lines were trisomic, and studies using microsatellite markers showed normal allelic segregation, which excluded uniparental disomy. The period of postnatal follow-up was characterised by a significant growth deficit (height and head circumference were less than the 3(rd) centile) and by mental retardation. The present case is compatible with other earlier reports that showed that the levels of trisomy 22 are tissue-specific and are of little help in establishing the prognosis of the chromosomal abnormality.

Ocular manifestations of mosaic trisomy 22: A case report and review of the literature

Mosaic trisomy 22 is rare, but can be compatible with prolonged life. Patients with mosaic trisomy 22 usually present with intrauterine growth retardation, mental retardation, failure to thrive, and craniofacial asymmetry. We report the case of a five-year-old boy who had a birth weight of 3.8 kg and normal developmental milestones. He presented with unilateral ocular manifestations of ptosis, double elevator palsy, high myopia, and choroidal coloboma involving the macula. Cytogenetic evaluation showed a low level of trisomy 22 in peripheral blood lymphocytes (1 in 100) and in cultured fibroblasts from a conjunctival biopsy of the affected eye (1 in 60). Our case demonstrates the value of chromosomal analysis of the tissues involved rather than just karyotyping of the blood lymphocytes to detect mosaicism in patients with localised and unilateral congenital malformations.

A 21 years follow-up of a girl patient with a pseudodicentric bisatellited chromosome 22 associated with partial trisomy 22pter-->22q12.1: clinical, cytogenetic and molecular observations

We present clinical and developmental data on a patient with a de novo recombinant pseudodicentric bisatellited chromosome 22 associated with a partial trisomy 22pter-22q12.1. The patient was evaluated at birth and followed-up until 21 years of age. Clinical findings include facial and digital dysmorphism, hydrocephalus and postnatal-onset growth deficiency. The patient showed bilateral microphthalmia with severe palpebral ptosis and coloboma of the iris and left optic nerve. She also has skeletal and neurological abnormalities, cholesteatoma and seizures. She had absence of speech, poor mobility, poor vision and required help with all daily living skills. Conventional chromosome GTG banded analysis showed that the proband had an abnormal karyotype:46,XX,add(22)(q13). Fluorescence in situ hybridization (FISH) analyses and microsatellite markers for DNA polymorphism study ascertained the karyotype as 46,XX,add(22)(q13.3).ish psu dic(22;22)(q13.3;q12.1)(D14Z1/D22Z1++, N25++, ARSA+, PCP22q+). The recombinant chromosome was stable and present in all cells examined. The paternal origin of the psu dic(22;22) chromosome was determined by using five highly polymorphic microsatellite markers located to the region of chromosome 22q11.2-22q13.33. A 22q13.3 monosomy was ruled out with 22q13.3 cosmid probes covering the terminal 22q-140Kb. The proband carried a recombinant pseudodicentric bisatellited chromosome psu dic(22;22)(q13.3;q12.1). To our knowledge, this is the first report of such rearrangement resulting in partial trisomy 22pter-22q12.1.

Non-mosaic trisomy 22: a report of 2 cases

Non-mosaic trisomy 22 is a common cause of first trimester miscarriage and has a livebirth incidence of 1 in 30,000-50,000. Consequently there is a paucity of information for counselling parents. Detection in the second trimester is rare. It is commonly associated with severe growth retardation and multiple structural abnormalities. Oligohydramnios is frequently seen and can make detection of other abnormalities difficult. The outlook is uniformly poor and survival beyond the first trimester may present management dilemmas. A thorough fetal assessment including high-resolution cytogenetics with or without FISH is required for counselling. Careful plans for intrapartum and neonatal management may be necessary. The recurrence risk is thought to be low but information is very limited as there have been no reported cases of recurrence. We present two case of non-mosaic trisomy 22 including the first to be diagnosed subsequent to investigation for a high serum screening Down's risk.

The preauricular sinus: a review of its clinical presentation, treatment, and associations

Preauricular sinuses (ear pits) are common congenital abnormalities. Usually asymptomatic, they manifest as small dells adjacent to the external ear near the anterior margin of the ascending limb of the helix, most frequently on the right side. Preauricular sinuses can be either inherited or sporadic. When inherited, they show an incomplete autosomal dominant pattern with reduced penetrance and variable expression. They may be bilateral, increasing the likelihood of being inherited, in 25-50% of cases. Preauricular sinuses are features of other conditions or syndromes in 3-10% of cases, primarily in association with deafness and branchio-oto-renal (BOR) syndrome. When other congenital anomalies coexist with these sinuses, auditory testing and renal ultrasound should be considered. Sinuses may become infected, most commonly with gram-positive bacteria, in which case their exudates should be cultured and appropriate antibiotics administered. Recurrent infection is a clear indication for complete excision and provides the only definitive cure. Recurrence rates after surgery range from 9% to 42%. Meticulous excision by an experienced head and neck surgeon minimizes the risk of recurrence.

Second-trimester sonographic findings in trisomy 22: report of 3 cases and review of the literature

OBJECTIVE

To describe cases of trisomy 22 detected prenatally on second-trimester sonography and to review the literature on similar cases, with special emphasis on the prenatal findings and pregnancy outcome.

METHODS

We performed follow-up second-trimester sonography and fetal karyotyping on 3 pregnant women who were referred because of abnormal findings on initial second-trimester scans. We also conducted a literature search for other reports of sonographic findings in trisomy 22.

RESULTS

Fetal abnormalities shown on sonography included nuchal thickening, mild generalized skin edema, an atrioventricular septal defect, an interventricular septal defect, edema of the scalp, face, and neck, severe left pleural effusion with a marked mediastinal shift, ascites, agenesis of the diaphragm, ambiguous genitalia, a single umbilical artery, bradycardia, a multicystic left kidney, and an absent right kidney. All 3 fetuses had karyotypes indicating trisomy 22. One pregnancy was terminated at the parents' request, and 2 ended in fetal death at 23 and 26 weeks. Our literature search revealed only 1 previous report of second-trimester sonographic diagnosis of trisomy 22. We found 3 other reports describing prenatal diagnosis in the third trimester, but only limited information on the sonographic findings was available.

CONCLUSIONS

Second-trimester sonography provides valuable clues for the prenatal diagnosis of several chromosomal disorders, including trisomy 22. Prenatal karyotyping is warranted if fetal growth restriction is detected in the second trimester, especially if associated with congenital defects.

Unexpected survival in a case of prenatally diagnosed non-mosaic trisomy 22: Clinical report and review of the natural history

Over 30 cases of complete non-mosaic trisomy 22 have been reported in the literature in the last 20 years [Crowe et al., 1997: Am J Med Genet 71:406-413]. Twenty-two infants were liveborn with an average life expectancy of four days. Of these, nine survived beyond the first two weeks of life. The life span ranged from minutes to 3 years of age. We report a case of an infant diagnosed prenatally with complete non-mosaic trisomy 22. Options such as aggressive medical/surgical intervention or limiting interventions to symptomatic care including home hospice were discussed openly. Given this information, the family elected to provide minimal supportive measures with pediatric hospice. The infant lived for 2 months with her family before her death. Numerous medical and surgical complications are associated with this disorder. Both the family and the medical team must be prepared for in utero fetal demise, stillbirth, or for limited life expectancy. Proper management, therefore, depends upon an understanding of the diagnosis.

Prenatal diagnosis of mosaic ring chromosome 22 associated with cardiovascular abnormalities and intrauterine growth restriction

OBJECTIVES

To present the prenatal diagnosis and perinatal findings of mosaic ring chromosome 22.

CASE

Amniocentesis was performed at 18 gestational weeks because of an advanced maternal age. Cytogenetic analysis of the cultured amniotic fluid cells revealed mosaicism for ring chromosome 22, 45,XX,-22[6]/46,XX,r(22)(p13q13.31)[15]. Abnormal fetal sonographic findings included small for gestational age, a ventricular septal defect, and truncus arteriosus. The pregnancy was terminated. Additional phenotypic findings included hypertelorism, epicanthal folds, and abnormal ears. Cytogenetic analysis of the cord blood lymphocytes revealed a complex mosaic karyotype, 45,XX,-22[7]/46,XX,r(22)(p13q13.31)[82]/46,XX,idic r(22)(p13q13.31;p13q13.31)[11]. Cytogenetic analysis of the hepatocytes also revealed mosaic r(22) with mosaicism for idic r(22) and monosomy 22. The deletion of distal 22q and the duplication of 22q11.2 on idic r(22), and the distal 22q deletion on r(22) were demonstrated by fluorescent in situ hybridization (FISH) analysis using 22q terminal probes at 22q13 and a DiGeorge syndrome critical region probe at 22q11.2. The breakpoint on distal 22q13 and the extent of the duplication of 22q on idic r(22) was determined by examining polymorphic markers specific for chromosome 22 using quantitative fluorescent polymerase chain reaction assays. The chromosomal aberration was of maternal origin.

CONCLUSION

Molecular and FISH studies allow a better delineation of some prenatally detected aneuploidy syndromes and help elucidate the genetic pathogenesis. Fetuses having mosaic r(22) with a low level mosaicism for r(22) duplication/deletion may present cardiovascular abnormalities and intrauterine growth restriction on prenatal ultrasound.

A rare case: mosaic trisomy 22

A 9-year-old female child of healthy parents (mother: 43 years, father: 44 years) was referred to our center because of severe mental retardation. While pedigree analysis was not contributory, two older sibs were normal and healthy. Physical examination revealed facial dysmorphism, microcephaly and hyperflexibility of all joints. Her chromosome constitution showed a mosaic pattern; mos 46,XX[98]/47,XX,+22[2]. So skin biopsy was performed and mosaic trisomy 22 was confirmed with FISH analysis (46,XX[73]/47,XX,+22[27]). Physical features of this case seemed consistent with her mosaic constitution. This report would be a demonstrative example to show the significant contribution of FISH in states of mosaicism.

Maternal uniparental disomy for chromosome 22 in a child with generalized mosaicism for trisomy 22

We report on a case of generalized mosaicism for trisomy 22. At chorionic villus sampling (CVS) in the 37th week of pregnancy, a 47,XX,+22 karyotype was detected in all cells. The indication for CVS was severe unexplained symmetrical intrauterine growth retardation (IUGR) and a ventricular septal defect (VSD) was noted. In cultured cells from amniotic fluid taken simultaneously, only two out of ten clones were trisomic. At term, a growth-retarded girl with mild dysmorphic features was born. Lymphocytes showed a normal 46,XX[50] karyotype; both chromosomes 22 were maternal in origin (maternal uniparental disomy). Investigation of the placenta post-delivery using fluorescence in situ hybridization showed a low presence of trisomy 22 cells in only one out of 14 biopsies. In cultured fibroblasts of skin tissue, a mosaic 47,XX,+22[7]/46,XX[25] was observed. Clinical follow-up is given up to 19 months.

Fryns syndrome phenotype and trisomy 22

Trisomy 22 was detected in a 32-week-old fetus born to an overweight mother with hypertension. Severe intrauterine growth retardation was associated with phenotypic manifestations of Fryns syndrome: diaphragmatic hernia, facial defects, and nail hypoplasia with short distal fifth phalanges. This is the second report of congenital diaphragmatic hernia in trisomy 22. This case demonstrates the importance of karyotyping malformed fetuses or newborns, even if a nonchromosome syndrome seems identifiable on clinical grounds. To date, at least 10 cases of Fryns syndrome have been reported without chromosome analysis.

Clinical and molecular studies in full trisomy 22: further delineation of the phenotype and review of the literature

Trisomy 22 is commonly found among spontaneous abortions, second in frequency of occurrence only to trisomy 16. Most earlier reports of surviving trisomy 22 cases in the literature are thought to represent the product of unbalanced 11;22 translocations or the result of undetected mosaicism, since this condition is thought to manifest early embryonic or fetal lethality. We present two strikingly similar cases of non-mosaic trisomy 22 surviving to late gestation. In this paper we emphasize the unique phenotype of this trisomy which included intrauterine growth retardation, microcephaly, broad flat nasal bridge with epicanthal folds and ocular hypertelorism, microtia, variable cleft palate, webbed neck, congenital heart defects involving anomalous great vessels, anorectal and renal anomalies, and hypoplastic distal digits with thumb anomalies. We also explore why some cases survive to late gestation. Confined placental mosaicism, a frequent finding in other lethal trisomies, has been ruled out in one of the cases. Molecular studies done to assess the parental origin of the extra chromosome in the other case showed that the non-disjunction originated during maternal meiosis II. Parental origin of the extra chromosome does not seem to play a role in late survival for trisomy 22.

Trisomy 22 and facioauriculovertebral (Goldenhar) sequence

We report on an infant girl born with complete trisomy 22 and left hemifacial microsomia, ear anomaly, and limbal and epibulbar complex choristoma. Trisomy 22 was confirmed by prometaphase chromosome analysis and in situ hybridization. This patient extends the list of chromosome abnormalities associated with apparent Golenhar sequence and emphasizes the importance of chromosome analysis in the investigation of patients with this condition. A detailed ophthalmopathological investigation is reported.

Trisomy 22 confirmed by fluorescent in situ hybridization

We report on a newborn girl with multiple congenital anomalies, whose G-banded chromosome analysis showed complete trisomy 22. Chromosome painting using a whole-chromosome painting probe for chromosome 22 confirmed that neither chromosome 22 was involved in a cryptic translocation.

Placental mosaicism in a case of 46,XY,-22,+t(22;22)(p11;q11) or i(22q) diagnosed at amniocentesis

46,XY,-22,+t(22;22)(p11;q11) or i(22q) was diagnosed in 15/15 cells from two cultures from the amniotic fluid culture of a 31-year-old patient whose fetus demonstrated cystic hygroma on ultrasound. Cytogenetic studies performed on fetal skin from the abortus revealed the same karyotype as that seen on amniocentesis, but the placenta demonstrated a 46,XY/46,XY,-22,+t(22;22) or i(22q) mosaicism, with 65 per cent of the cells being 46,XY. This case provides an example of placental mosaicism for a normal male karyotype, while the fetus demonstrated non-mosaic trisomy 22.

The ocular pathology of trisomy 22: report of two cases and review

Two cases of full trisomy 22 with the associated gross and microscopic pathology are reported. These cases demonstrate the typical craniofacial and organ system anomalies previously reported in trisomy 22 but also exhibit uveal colobomas that, within the spectrum of chromosome 22 anomalies, are usually restricted to the so-called "cat eye" syndrome. The attendant microscopic ocular findings represent, the best of our knowledge, the first such report in the literature.

Trisomy 22 with holoprosencephaly: a clinicopathologic study

Trisomy 22 (47, XY, +22) was found at 17 weeks gestation in one fetus of a twin gestation. The karyotypes of both parents and of the other twin were normal. Abnormal prenatal findings included maternal pre-eclampsia, fetal growth retardation, and progressive intracranial sonolucency of the trisomic fetus. Delivery by cesarean section at 36 weeks gestation yielded a normal healthy female weighing 2,822 grams and a markedly macerated dysmorphic male weighing 642 grams. Holoprosencephaly was found in the trisomic fetus, an unusual feature in trisomy 22. Additional findings in this case are compared to other findings in the literature.

Trisomy 22 mosaicism limited to skin fibroblasts in a mentally retarded, dysmorphic girl

Less than 10 cases of trisomy 22 mosaicism have been reported. The patients have clinical features in common with both Down's and Turner's syndromes. We report on a 12-year-old girl, in whom the GFR-stimulated gonadotropine response suggested ovarian dysgenesis, although ovarian structures could be demonstrated by ultrasound. The diagnosis of trisomy 22 mosaicism was established by chromosome analysis of cultured skin fibroblasts following a negative lymphocyte culture.

Trisomy 22 in a liveborn infant with multiple congenital anomalies

We report on the third confirmed case of trisomy 22 in a liveborn infant. High-resolution banding studies ruled out translocations such as the relatively common t(11;22). The infant shared many manifestations with other reported cases of trisomy 22 (e.g., growth deficiency, microcephaly, micrognathia, ear malformations, cleft palate, and congenital heart defect) and some manifestations in common with dup 22. Trisomy 22 appears to cause a severe malformation syndrome, and survival to term is rare.

Trisomy 22: no longer an enigma

We describe a live-born male with 47,XY,+22. He had multiple congenital anomalies, severe growth retardation and psychomotor delay. Physical manifestations included broad nasal bridge, epicanthic folds, micrognathia, long philtrum, cleft palate, microcephaly with prominent occiput, apparently low-set malformed ears, heart murmur, genital anomaly, clinodactyly of the fifth fingers, and a low total finger ridge count. He died just before his 3rd birthday. Chromosome analysis by multiple banding techniques based on lymphocyte and fibroblast cultures confirm that the boy had complete trisomy 22.

Duplication of distal 22q

We report on three patients with duplication of distal 22q. One patient is a de novo carrier of the translocation t(21;22) (p13;q11), the other two are offspring of a translocation carrier t(10;22) (q26;q12). The clinical manifestations of these patients demonstrate the variability of the dup(22q) syndrome.

Trisomy 22 mosaicism with normal blood chromosomes. Case report with literature review

A female infant with growth failure, microcephaly, hypertelorism, epicanthal folds, preauricular pit, congenital heart defect, hypotonia, and delayed development is reported. Trisomy 22 mosaicism (46,XX/47,XX,+22) was found in cultured skin fibroblasts but not in blood lymphocytes. Trisomy restricted to skin fibroblasts is uncommon.

Trisomy 22 in a newborn with multiple malformations

A case of complete trisomy 22 in a live-born female child with multiple malformations is reported. The karyotype of the index patient had 46 chromosomes, with one chromosome 22 missing and one supranumerary metacentric chromosome. Different banding methods and in situ hybridization revealed that the extra chromosome consists of the long arms and a part of the short arms of two chromosomes 22. Our report supplies further proof that a fetus with complete trisomy 22 can occasionally survive to term, but the condition is not compatible with life over a long period.

Trisomy 22 mosaicism syndrome and Ullrich-Turner stigmata

Mosaic trisomy 22, ascertained in three unrelated patients, was found to be associated with body asymmetry and signs of the Ullrich-Turner syndrome including short stature, ptosis, webbed neck, nevi, cubitus valgus, dysplastic nails, malformed great vessels, and abnormal ovaries. These anomalies in trisomy 22 mosaicism have not been emphasized heretofore. In each of our patients, trisomy 22 mosaicism was found only in fibroblasts. In one patient, the trisomy resulted from a paternal first meiotic nondisjunction, and in the 46,XX cells, both chromosomes 22 were of paternal origin.

Incomplete trisomy 22. I. Familial 11/22 translocation with 3:1 meiotic disjunction. Delineation of a common clinical picture and report of nine new cases from six families

A syndrome due to 3:1 meiotic segregation of balanced 11/22 translocation is defined from nine personally observed patients and 22 cases from the literature with apparently the same aberration. Frequent findings include a characteristic face with deep-set eyes, flat nose, prominent upper lip, receding mandible and preauricular pits or tags, male genital hypoplasia, anal atresia or other anomalies of the anus, cleft palate, and congenital heart defect. Less frequent are severe reduction of the auricles, an additional pair of ribs, and hypoplasia of the diaphragm. Perinatal mortality is high. Growth is usually and psychomotor development is invariably and severely delayed. Balanced 11/22 translocations are apparently disproportionally frequent; as the balanced rearrangement is not easy to detect, it is important to be aware of it at the family investigation of cases with extra chromosomes similar to a No. 22 or 22q-. The unbalanced products are most probably trisomic for both a segment of 22 (22q-) and a distal segment of 11q; the exact determination of the breakpoints is not possible at present due to the similar banding characteristics of the two segments involved in the translocation.

Incomplete trisomy 22. II. Familial trisomy of the distal segment of chromosome 22q in two brothers from a mother with a translocation, t(6;22)(q27;q13)

Two brothers with duplication of the distal segment of 22q inherited from a t(6;22)(q27;13) translocation carrier mother presented with intrauterine growth retardation, congenital hydrocephalus, cleft palate, genital hypoplasia with cryptorchidism and hypospadias, and similar facial features including mongoloid position of eyeaxes, hypertelorism, small nose with prominent bridge, prominent upper lip, and small mandible. In addition the second sib revealed renal hypoplasia, arrhinencephaly and pentalogy of Fallot. The patients died at ages eight days and one day, respectively. The two brothers appear to be the first instances of familial trisomy 22q13 leads to qter.