Partial deletion of long arm of chromosome 11: del (11) (q23)

A novel case of bilateral high myopia, cataract, and total retinal detachment associated with interstitial 11q deletion

PURPOSE

Jacobsen syndrome, also known as 11q deletion syndrome, is a rare condition characterized by multiple anomalies, including developmental delay, cardiac abnormalities, blood dyscrasias, distal limb abnormalities, craniofacial anomalies, and variable ophthalmic manifestations. The syndrome's phenotype is due to a terminal deletion and is usually severely debilitating, frequently associated with fatality. Interstitial deletions, not involving the terminal end, have been associated with a more variable and less severe phenotype.

METHODS

Herein, we describe a case of interstitial 11q deletion in a 16 year-old female with associated systemic and craniofacial abnormalities as well as a novel combination of ocular findings, specifically strabismus, high myopia, bilateral cataracts, and bilateral total retinal detachments.

RESULTS

This case report highlights the necessity for a detailed ophthalmic examination of patients with both interstitial and terminal deletions of the long arm of chromosome 11.

The Ocular Manifestations of Jacobsen Syndrome: A Report of Four Cases and a Review of the Literature

PURPOSE

We report ophthalmic manifestations in four Jacobsen syndrome cases, review the literature, and suggest phenotype-genotype correlations.

METHODS

Chart review of Ocular Genetics Program patients at The Hospital for Sick Children, Toronto, Canada.

RESULTS

Four del11qter cases are presented. Hypertelorism/telecanthus, abnormally slanted palpebral fissures, abnormal retinal findings, nasolacrimal duct obstruction, anomalous extraocular muscles, amblyopia, and microcornea were found.

CONCLUSIONS

We report typical findings and novel ocular presentations. Visual prognosis is generally good. Retinal dysplasia and coloboma seem associated with del11q23. ABCG4, NCAM, and Mfrp are candidate genes in this region that theoretically may be disrupted.

Prenatal diagnosis of mosaicism for 11q terminal deletion

The phenotype of 11q terminal deletion also known as Jacobsen syndrome is a clinically well known entity whose diagnosis in infancy and childhood is based on clinical examination, hematological and cytogenetic findings. Hematological features in Jacobsen syndrome are very similar to those reported in Paris-Trousseau syndrome (PTS) which is also associated with11q terminal deletion. Karyotype analysis shows a variable terminal deletion from 11q23 sub-band extending to the telomere. Most often in patients with Jacobsen syndrome, this chromosomal deletion is present in all metaphases. We report on the identification of a distal 11q deletion in mosaic (20% of deleted cells) in a fetus ascertained after amniocentesis for maternal serum screening test indicative for Down syndrome. The present case is the third prenatal diagnosis of a mosaic for a distal 11q deletion with the lowest mosaicism rate. The 2D-ultrasound examination and cord blood hematological studies were useful to estimate the prognosis at term, considering the contribution of the mosaicism rate to the phenotypic variability in Jacobsen syndrome. The identification of mosaicism for distal 11q deletion is a very rare event in prenatal diagnosis. This case illustrates the complexity in genetic counselling for prenatally ascertained partial monosomy 11qter in mosaic.

Jacobsen syndrome: report of a patient with severe eye anomalies, growth hormone deficiency, and hypothyroidism associated with deletion 11 (q23q25) and review of 52 cases

We have evaluated a patient with Jacobsen syndrome. The patient presented with growth retardation, hypotonia, trigonocephaly, telecanthus, downward slanting palpebral fissures, bilateral inferior colobomas (of the iris, choroid, and retina), hydrocephalus, central nervous system (CNS) abnormalities, and an endocardial cushion defect, features commonly seen in Jacobsen syndrome. Endocrine evaluation showed growth hormone deficiency and central hypothyroidism. Chromosome analysis showed a 46,XX,del(11)(q23q25) de novo karyotype. Cytogenetically, the deletion appeared to include most of bands 11q23 and q24 and a portion of q25. Using chromosome specific paint probe, a combination of chromosome 11 centromere, telomere, and region specific cosmid probes from 11q14.1-14.3, 11q23.3, and 11q24.1, we have localised the deletion breakpoint to q24.1. Phenotype-karyotype correlation of patients with Jacobsen syndrome and specific deletions of chromosome 11q has enabled us to suggest that the critical region for this syndrome lies in close proximity to cytogenetic band 11q24. Although growth retardation is a consistent finding in 11q deletion syndrome, the presence of hypothalamic-pituitary hormone deficiency has not been reported previously.

Two craniosynostotic patients with 11q deletions, and review of 48 cases

Many chromosomal abnormalities have craniofacial manifestations. One such abnormality, partial monosomy of chromosome 11q, is associated with metopic synostosis and resultant trigonocephaly. We reviewed 48 published cases of 11q deletions and translocations. Eighty percent were associated with abnormal head shape. Also commonly found were hypertelorism, ptosis of the eyelids, wide or low nasal bridge, apparently low-set malformed ears, down-turned mouth, micro/retrognathia, digital and cardiac anomalies, and psychomotor retardation. We report on two patients referred for abnormal head shape. The first case had brachycephaly, flat occiput, hypertelorism, and maxillary hypoplasia. Karyotype was 46,XY,del(11)(q24.1-->qter). The second patient had trigonocephaly, hypotelorism, posteriorly angulated ears, horizontal crease below his lower lip, syndactyly, shawl scrotum, cryptorchidism, and inguinal hernias. Karyotype showed partial trisomy of chromosome 4q as well as partial monosomy of 11q [46,XY,11,+der(11)t(4;11) (q31.3;q25)], a combination not previously reported. Deletions of 11q appear to produce a wide spectrum of abnormalities.

Deletion (11)(q14.1q21)

We report on a 4-year-old girl with moderate developmental delay, horseshoe kidney, bilateral duplication of the ureters with right upper pole obstruction, hydronephrosis and nonfunction, and subsequent Wilms tumor of the right lower pole. She had an interstitial deletion of the long arm of chromosome 11 involving the region 11(q14.1q21).

Monosomy 11q: report of two familial cases and review of the literature

We present four children from two families with the typical 11q- phenotype resulting from an unbalanced segregation of a parental translocation. In the first family, the father had a 46,XY,t(5;11)(q24;q23.3) constitution. The father of the three other children had a 46,XY,t(11;17)(q23;p13) translocation. Despite associated partial deletion, three of the children had a typical 11q- phenotype. The fourth one, whose pregnancy was terminated in the second trimester, had a hypoplastic left heart but no other considered gross anomalies. A review of 36 previous cases, including 5 due to translocations (4 familial rearrangements, and 1 of unknown origin) is given with emphasis on the relationships between break-points and phenotype. Undescribed manifestations in our patients include agenesis of corpus callosum adactyly and malrotation of the gut.

Unbalanced mosaic karyotypes with different structural abnormalities involving a common chromosome region: report of two cases

We report on 2 cases with different de novo unbalanced mosaic karyotypes in which each cell line had a different structural abnormality involving a common chromosome region: 46,XX,del(11)(q23.3)/46,XX.-11, + der(11)t(11;?)(q23.3;?) and 46,X,idic(Xq)/46,X,idic(Xq),-12, + der(12)t(X;12)(p11.2;p13.3). Molecular-cytogenetic analysis confirmed the origin of the derivative 12 chromosome in the latter. We present a literature review of reports with mosaic cell lines of structural chromosome abnormalities that share the same chromosome breakpoint.

Holoprosencephaly, ear abnormalities, congenital heart defect, and microphallus in a patient with 11q- mosaicism

We report on a newborn male with deletion of part of 11q, the 27th reported case. Our patient had some of the clinical characteristics of the 11q- syndrome, but his male gender, liveborn status, q21 breakpoint, and mosaicism were unusual. In addition, he demonstrated holoprosencephaly, with cyclopia and arhinencephaly, manifestations previously unreported in the 11q- syndrome. We discuss the above points and review the literature on 11q-.

Distal 11q monosomy. The typical 11q monosomy syndrome is due to deletion of subband 11q24.1

In this paper we describe two new patients with distal 11q monosomy and precisely localize breakpoints using high resolution banding techniques. The findings in these two patients further contribute to the precise localization of the crucial band for 11q monosomy syndrome as being at 11q24.1. A very distal 11q24.2 deletion in the second patient resulted in a completely different phenotype.

Chromosomal abnormalities associated with congenital contractures (arthrogryposis)

In a study of 350 patients with multiple congenital contractures (arthrogryposis), 80 (23%) patients had mental retardation or were developmentally delayed. Out of that group of 80 patients, 13 (16%) were found to have abnormal karyotypes. Two of the thirteen had a family history of chromosomal abnormalities without congenital contractures, therefore, 11 patients had chromosomal anomalies which appeared to be associated with the congenital contractures. Five of the eleven (45%) had chromosome mosaicism, three of those had tissue mosaicism. Two had abnormal skin fibroblast cell lines and normal peripheral leukocyte chromosome studies and one had a normal bone marrow karyotype with abnormal peripheral leukocyte chromosome studies. Chromosome studies were done in these patients with congenital contractures because of developmental delay and multisystem involvement, or recognition of clinical features typical of a chromosomal syndrome. We recommend first lymphocyte; and if those are normal, then fibroblast studies be done on all patients with multiple joint contractures and developmental delay, particularly if unusual facial features or multisystem abnormalities are present.

New anomalies found in the 11q-syndrome

The cytogenetic analysis of an infant with multiple congenital anomalies revealed a small deletion of the long arm of one No. 11 chromosome: 46XX del 11 (q23-q25). The main clinical manifestations included: trigonocephaly, flat broad nasal bridge, micrognathia, carp mouth, hypertelorism, low set ears, severe congenital heart disease, anomalies of limbs and external genitalia. In comparison to the previously reported cases of 11q-, the patient presented here had congenital anomalies not described before, including severe affected urogenital system, hypoplasia of the adrenal, accessory spleens and mild hydrocephaly.

Brief clinical report: ring-11 chromosome: phenotype-karyotype correlation with deletions of 11q

The cytogenetic evaluation of a female infant with congenital anomalies led to the identification of the second reported case of a ring-11 chromosome. Unlike the previously described case, in which the patient had only minimal clinical findings and no demonstrable loss of material from the ring, our patient had numerous anomalies that were associated with a substantial deficiency of 11q material. The different phenotypes in these two cases represent variation in the amount and location of the chromosomal material lost during the genesis of the ring. The manifestations of this patient and the deletion of region q24 leads to qter from the ring-11 identify a specific chromosome deletion syndrome referred to as del (11q) syndrome.

Brief clinical report: deletion of the long arm of chromosome 11, [del(11)(q23)]

We report sporadic occurrence of deletion of the long arm of chromosome 11 (q23 leads to qter) in a male newborn infant with intrauterine growth retardation, craniofacial, cardiac, and orthopedic abnormalities and neonatal death but without genital abnormalities. This deletion is seen predominantly in females; here we emphasize the importance of an XX sex chromosome constitution as a factor determining phenotypic expression of and survival in the del(11q) syndrome. We also provide a description of the cardiovascular system from postmortem examination. The cardiac findings are similar to those of two previously autopsied cases and will assist in early clinical diagnosis of the 11q-syndrome.

Deletion of the long arm of chromosome 11: a clinical entity

A deletion of the long arm of chromosome No. 11, an aberration undetectable in conventional chromosome staining, was identified with Giemsa banding in a female infant with multiple congenital anomalies. A survey is given of the clinical findings in the few cases so far reported.