Prenatal diagnosis of terminal deletion 7q and partial trisomy 3p in fetuses with holoprosencephaly

Chromosome aberrations, mendelian mutations and exogenous agents can cause holoprosencephaly. Therefore, etiologic evaluation of holoprosencephaly is necessary for obstetricians and genetic counselors, once a prenatal diagnosis of holoprosencephaly has been made. We present four pregnancies in three women in which routine sonographic examinations led to the prenatal diagnosis of holoprosencephaly. Prenatal cytogenetic analysis and fluorescence in situ hybridization demonstrated a 46, XY, del(7)(pter→q32:) and a 46, XY, der(2)t(2;3)(q37;p21)pat karyotype respectively in two fetuses with cyclopia, and a 46, XX, der(2)t(2;3)(q37;p21)pat and a 46, XX, der(7)t(3;7)(p23;q36) karyotype respectively in two fetuses with premaxillary agenesis. In conclusion, terminal deletion 7q and partial trisomy 3p in holoprosencephalic fetuses indicates that genes contributing to craniofacial development reside in these critical regions. Proper prognostic evaluation in further pregnancies requires expertise in cytogenetics and genetic counseling.     

Caudal deficiency sequence in 7q terminal deletion

We describe a male infant with signs of caudal deficiency sequence. In addition, he showed growth retardation, microcephaly, prominent forehead, bulbous nose tip, large dysplastic ears, hypospadia, partial sacral agenesis, and neurologic bladder dysfunction. Chromosome examination showed a terminal 7q deletion 46,XY,del(7)(pter----q32:). Four previous reported cases of 7q terminal deletion and signs of caudal deficiency are reviewed. Chromosome aberrations may, at least in some cases, be responsible for developmental defects.     

Two patients with chromosome 6q terminal deletions with breakpoints at q24.3 and q25.3.

We report on 2 patients with de novo terminal deletion of 6q. The first was a 4-month-old boy whose karyotype was 46,XY,del(6)(q24.3); the second a 2-year-old girl whose karyotype was 46, XX, del(6)(q25.3). The main anomalies in both patients included mental retardation, minor craniofacial and cerebral anomalies, and cardiac defects. The characteristic manifestations were imperforate anus in the first patient, and retinitis proliferans and a triatrial heart in the other. Comparison of clinical findings of our 2 patients with those of 18 previously reported patients with similar phenotypes suggests that terminal deletion of the 6q23 or 6q25 band is critical in producing the main anomalies of del(6q) syndrome.     

Two patients with chromosome 6q terminal deletions with breakpoints at q24.3 and q25.3

We report on 2 patients with de novo terminal deletion of 6q. The first was a 4-month-old boy whose karyotype was 46, XY, del(6)(q24.3); the second a 2-year-old girl whose karyotype was 46, XX, del(6)(q25.3). The main anomalies in both patients included mental retardation, minor craniofacial and cerebral anomalies, and cardiac defects. The characteristic manifestations were imperforate anus in the first patient, and retinitis proliferans and a triatrial heart in the other. Comparison of clinical findings of our 2 patients with those of 18 previously reported patients with similar phenotypes suggests that terminal deletion of the 6q23 or 6q25 band is critical in producing the main anomalies of del(6q) syndrome. © 1992 Wiley-Liss, Inc.     

Partial monosomy of distal 10q: three new cases and a review.

We report on 3 patients with partial deletions of the long arm of chromosome 10-46,XY,del (10)(q26.2), 46,XX,del(10) (q25.3q26.3) or 46,XX,del(10)(q26.1), and 46,XX,del (10)(q26.1). They are compared with other known cases with interstitial or terminal deletions involving chromosome bands 10q25 or q26. Unique manifestations are identified, including scoliosis and a severe behavior disorder with attention deficit and hyperactivity in a 12-year-old boy as well as patchy alopecia in a 6-year-old patient.     

Cebocephaly-holoprosencephaly in a newborn girl with a terminal 7q deletion [46,XX,del(7)(pter→q32:)]

Cytogenetic study of a day-old infant showed a terminal del(7q): 46,XX,del(7)(pter→q32:). This infant had cebocephaly with holoprosencephaly. These clinical findings are atypical for the 7q – syndrome, in which patients usually have growth and mental retardation with few facial abnormalities.     

Proximal interstitial deletion of 7q: a case report and review of the literature

A male infant with multiple congenital anomalies was found to have a deletion of 7q [46,XY,del(7)(pter----q11.2::q22----qter)]. The father had a balanced rearrangement involving chromosomes 7 and 9, interpreted as 46,XY,dir ins(9;7), (9pter----9p12::7q22----7q11.2::9p12----++ +9qter;7pter---- 7q11.2::7q22----7qter). C-banding showed that the rearrangement occurred as a new event in the paternal grandfather's germ-line. Including the present patient, 16 cases of proximal 7q deletion (q11----q21/q22) have been described to date. This is a sufficient number of cases to permit comparison of manifestations to attempt delineation of karyotype-phenotype relationships in different proximal interstitial deletions of 7q.     

9p Deletion and distal 9q duplication due to a paternal pericentric inversion 9(p22q32)

A female infant with 46,XX,rec(9), dup q,inv(9)(p22q32)pat is presented. She had a duplication from 9q32 to qter and a deletion from 9q22 to 9pter. Phenotypical abnormalities observed corresponded with features noted in cases with distal dup (9q), while pathognomonic features of del(9p) syndrome were not observed.     

9p deletion and distal 9q duplication due to a paternal pericentric inversion 9(p22q32)

A female infant with 46,XX,rec(9), dup q,inv(9)(p22q32)pat is presented. She had a duplication from 9q32 to qter and a deletion from 9p22 to 9pter. Phenotypical abnormalities observed corresponded with features noted in cases with distal dup (9q), while pathognomonic features of del(9p) syndrome were not observed.     

Boy with a chromosome del (3)(q12q23) and Blepharophimosis syndrome

We report on a 6-year-old boy with de novo 46, XY, del(3)(q12q23) and bilateral blepharo-phimosis, ptosis, epicanthus inversus, in addition to multiple other anomalies. Since 4 previously reported cases of interstitial deletion of 3q involving 3q23 band are clinically similar, we propose this blepharophimosis sequence due to 3q23 deletion as a further “contiguous gene syndrome”.     

Boy with a chromosome del (3)(q12q23) and blepharophimosis syndrome.

We report on a 6-year-old boy with de novo 46,XY,del(3)(q12q23) and bilateral blepharophimosis, ptosis, epicanthus inversus, in addition to multiple other anomalies. Since 4 previously reported cases of interstitial deletion of 3q involving 3q23 band are clinically similar, we propose this blepharophimosis sequence due to 3q23 deletion as a further "contiguous gene syndrome."     

Proximal 7q interstitial deletion in a severely mentally retarded and mildly abnormal infant.

We describe a boy with an interstitial deletion of 7q [46,XY,del(7)(pter-->q11.21::q11.23-->qter)] and severe mental retardation, bilateral inguinal hernias, plagiocephaly, and mildly abnormal facial appearance. This is the 21st case report involving a proximal 7q deletion, but the first report of this specific deletion in the absence of Zellweger syndrome. Specific genotype-phenotype correlations are still not possible for this region of chromosome 7.     

Chromosome 6q deletions: a report of two additional cases and a review of the literature

Here we report on two additional cases of distal 6q deletions with one case showing a terminal deletion of chromosome 6 (46,XY, del(6)(pter----q26:)) and one case showing an interstitial deletion of chromosome 6 (46,XY, del(6)(pter----q23::q25----qter)). The association of retinal abnormalities in 6q deletions is supported, and the additional manifestations of skin hyperextensibility, sacral abnormality, and imperforate anus are described.     

Proximal 7q interstitial deletion in a severely mentally retarded and mildly abnormal infant

We describe a boy with an interstitial deletion of 7q [46,XY,del(7)(pter→q11.21::q11.23→qter)] and severe mental retardation, bilateral inguinal hernias, plagiocephaly, and mildly abnormal facial appearance. This is the 21st case report involving a proximal 7q deletion, but the first report of this specific deletion in the absence of Zellweger syndrome. Specific genotype-phenotype correlations are still not possible for this region of chromosome 7. © 1992 Wiley-Liss, Inc.     

Disappearance of a highly unusual clone, 46,XY,del(7)(p12),t(9;22)(q34;q11) in chronic myeloid leukemia after treatment with recombinant interferon and cytosine arabinoside.

A patient with the typical features of the stable phase of chronic myeloid leukemia (CML) displayed two karyotypically related subclones. In addition to the t(9;22), cells from one clone contained a deletion of the short arm of chromosome 7, del(7)(p12), [46,XY,del(7)(p12),t(9;22)(q34;q11)]; the other contained only the standard translocation [46,XY,t(9;22)(q34;q11)]. Cells with a deletion of the short arm of chromosome 7 at band p12 as the only additional abnormality have not been observed previously in CML. Conventional chemotherapy with hydroxyurea and then with recombinant interferon-alpha (rIFN-alpha) did not reduce the population of either subclone. However, after treatment with a combination of rIFN-alpha and low-dose cytosine arabinoside (LoDac) continuously infused subcutaneously (s.c.), cells from the clone with the deleted chromosome 7 disappeared and normal metaphases were demonstrable.     

Familial partial 7q monosomy resulting from segregation of an insertional chromosome rearrangement.

A family with an insertional type of chromosome rearrangement involving chromosomes 7 and 13 is reported. An interstitial deletion of a segment of chromosome 7 (7q32 leads to 34) had been inserted into the long arm of chromosome 13 at breakpoint q32. Segregation of this chromosome rearrangement gave rise to three subjects who were monosomic for the involved segment of chromosome 7. The karyotypes were: 46,XX, or XY,der(7)ins(13;7) (q32;q32q34). All three subjects were mentally retarded and had minor dysmorphic features. The Kidd, Colton, and Kell blood group systems were investigated, but were not informative.     

Deletion of the long arm of chromosome 6: two new patients and literature review

Two children with a partial monosomy 6q are reported: a girl with an interstitial deletion [46, XX, del(6)(q16.2q23.1)], and a boy with a terminal deletion [46, XY, del(6)(q25.1)]. Both children presented with developmental delay, facial dysmorphism and a cardiac defect. The patients have been studied using G banding and cosmid probes specific for the long arm of chromosome 6. Clinical data are compared with patients reported in the literature.     

Familial reciprocal translocation, t(2;10)(p24;q26), resulting in duplication 2p and deletion 10q

We describe a familial reciprocal translocation between the distal part of the short arm of chromosome 2 and the long arm of chromosome 10. Five individuals in two generations had multiple congenital anomalies. Their karyotypes were 46, XX or XY,−10, + der(10), t(2;10)(p24;q26). Seven persons were balanced translocation carriers whose karyotypes were 46, XX or XY, t(2;10)(p24;q26). Common manifestations included mental retardation, strabismus, narrow high-arched palate, wide alveolar ridges, other facial abnormalities, genital abnormalities and mutism. The phenotype of the unbalanced individuals is compared to that of previously published cases of the syndrome of partial duplication 2p and to reported patients with partial deletion of 10q.     

Significance of a prenatally diagnosed del(10)(q23).

Structural chromosome mosaicism is rare. We report a case of prenatal mosaicism for a deletion of chromosome 10(q23). To our knowledge, there are only three reports of prenatally diagnosed cases of del(10)(q23). Two of these cases were due to an inherited fragile site. In the present case amniocentesis revealed 46,XY,del(10)(q23)[9]/46,XY[45]. Follow-up chromosome analysis of peripheral blood and placental tissue from a phenotypically normal liveborn male revealed the del(10)(q23) in only 3/100 blood cells grown in low-folate medium. It appears that prenatally diagnosed deleted (10q) mosaicism represents culture artifact and is not clinically significant.     

Cytogenetic findings in familial B-cell chronic lymphocytic leukemia: a report of two cases in a family

Familial B-cell chronic lymphocytic (B-CLL) leukemia has been defined as an entity epidemiologically different from sporadic B-CLL. Cytogenetic abnormalities in familial B-CLL, studied either by conventional cytogenetics or by interphase fluorescence in situ hybridization (i-FISH), have rarely been reported. We report a two-case family affected with B-CLL showing two different abnormal karyotypes detected by conventional cytogenetics [46,XX,del(7)(q32) and 46,XY,add(1)(p36),del(6)(q21)] but sharing a del(13)(q14) at the D13S319 locus, detected by interphase fluorescence in situ hybridization.