Chromosome 1p32-p31 deletion syndrome: prenatal diagnosis by array comparative genomic hybridization using uncultured amniocytes and association with NFIA haploinsufficiency, ventriculomegaly, corpus callosum hypogenesis, abnormal external genitalia

Short Communication

Chromosome 1p32-p31 deletion syndrome: Prenatal diagnosis by array

comparative genomic hybridization using uncultured amniocytes and

association with NFIA haploinsufficiency, ventriculomegaly, corpus

callosum hypogenesis, abnormal external genitalia, and intrauterine

growth restriction

Chih-Ping Chen

*

, Yi-Ning Su

, Yi-Yung Chen

, Schu-Rern Chern

, Yu-Peng Liu

,

Pei-Chen Wu

, Chen-Chi Lee

, Yu-Ting Chen

, Wayseen Wang

a

Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan b

Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan c

Department of Biotechnology, Asia University, Taichung, Taiwan d

School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan e

Institute of Clinical and Community Health Nursing, National Yang-Ming University, Taipei, Taiwan f

Department of Obstetrics and Gynecology, School of Medicine, National Yang-Ming University, Taipei, Taiwan g

Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan h

Department of Radiology, Mackay Memorial Hospital Hsinchu Branch, Hsinchu, Taiwan i

Mackay Medicine, Nursing and Management College, Taipei, Taiwan j_{Department of Bioengineering, Tatung University, Taipei, Taiwan}

Accepted 7 July 2011

Abstract

Objective: To present prenatal diagnosis of chromosome 1p32-p31 deletion syndrome with NFIA haploinsufficiency, ventriculomegaly, corpus

callosum hypogenesis, abnormal external genitalia, and intrauterine growth restriction and to review the literature.

Materials, Methods, and Results: A 26-year-old, primigravid woman was referred for amniocentesis at 30 weeks of gestation because of

hydrocephalus and short limbs. Prenatal ultrasound showed macrocephaly, prominent forehead, ventriculomegaly, corpus callosum hypogenesis,

micrognathia, and ambiguous external genitalia. Amniocentesis was performed, and array comparative genomic hybridization using uncultured

amniocytes revealed a 22.2-Mb deletion of 1p32.3-p31.1 [arr cgh 1p32.3p31.1 (55,500,291 bp

e77,711,982 bp)
1] encompassing the genes of

NFIA, GPR177, and 89 additional genes. Cytogenetic analysis revealed a karyotype of 46,XX,del(1)(p31.1p32.3)dn. At 33 weeks of gestation,

a dead fetus was delivered with a body weight of 1536 g (

<5

centile); relative macrocephaly; a broad face; prominent forehead; hypertelorism;

anteverted nostrils; micrognathia; low-set ears; and abnormal female external genitalia with labial fusion, labial hypertrophy, absence of vaginal

opening, and clitoral hypertrophy. Polymorphic DNA marker analysis determined a paternal origin of the deletion.

Conclusion: Prenatal diagnosis of ventriculomegaly with an abnormal corpus callosum should alert subtle chromosome aberrations and prompt

molecular cytogenetic investigation if necessary. Fetuses with chromosome 1p32-p31 deletion syndrome and haploinsufficiency of the NFIA

gene may present ventriculomegaly, corpus callosum hypogenesis, abnormal external genitalia, and intrauterine growth restriction in the third

trimester.

Copyright

Ó 2011, Taiwan Association of Obstetrics & Gynecology. Published by Elsevier Taiwan LLC. All rights reserved.

Keywords: Abnormal external genitalia; Chromosome 1p32-p31 deletion syndrome; Corpus callosum hypogenesis; Ventriculomegaly

* Corresponding author. Department of Obstetrics and Gynecology, Mackay Memorial Hospital, 92, Section 2, Chung-Shan North Road, Taipei, Taiwan. E-mail address:[email protected](C.-P. Chen).

Taiwanese Journal of Obstetrics & Gynecology 50 (2011) 345e352

www.tjog-online.com

1028-4559/$ - see front matter CopyrightÓ 2011, Taiwan Association of Obstetrics & Gynecology. Published by Elsevier Taiwan LLC. All rights reserved. doi:10.1016/j.tjog.2011.07.014

Introduction

Chromosome 1p32-p31 deletion syndrome [Online

Mende-lian Inheritance in Man (OMIM) 613735], a contiguous gene

deletion syndrome, is associated with haploinsufficiency of

the NFIA gene. The gene NFIA (OMIM 600727) locates at

1p31.3-p31.2 and encodes nuclear factor IA (NFIA) protein.

Chromosome 1p32-p31 deletion syndrome is characterized by

macrocephaly; hydrocephalus/ventriculomegaly; hypoplastic/

absent corpus callosum; developmental delay; urinary tract

defects such as vesicoureteral reflux and urinary incontinence;

facial dysmorphism of a broad face with prominent forehead,

low-set ears, a small mouth and chin, anteverted nostrils,

a high palate and sparse eyebrows, and variable features of

pigmentary retinopathy; inguinal hernia; cryptorchidism;

polydactyly; hip dysplasia; and cutis marmorata

[1,2]

. To date,

only seven cases with chromosome 1p32-p31 deletion

syndrome have been reported

[1

e5]

, and all were diagnosed in

infancy or childhood. Herein, we present an additional case,

which, to our knowledge, is the first prenatally diagnosed case

Fig. 1. (A) Ventriculomegaly; (B) macrocephaly with prominent forehead and micrognathia; and (C) corpus callosum hypogenesis with absence of cavum septum pellucidum on prenatal ultrasound at 30 weeks of gestation.

Fig. 2. (A) Ventriculomegaly and (B) hypoplasia of the splenium of corpus callosum (arrow) on ultrafast magnetic resonance imaging at 30 weeks of gestation. 346 C.-P. Chen et al. / Taiwanese Journal of Obstetrics & Gynecology 50 (2011) 345e352

Fig. 3. Oligonucleotide-based array comparative genomic hybridization shows a 22.2-Mb deletion from 1p32.3 to 1p31.1 [arr cgh 1p32.3p31.1 (55,500,291e77,711,982)
1] (arrow). arr cgh ¼ array comparative genomic hybridization.

with chromosome 1p32-p31 deletion syndrome. We also

review the literature.

Materials, methods, and results

A 26-year-old, primigravid woman was referred for

amniocentesis at 30 weeks of gestation because of

hydro-cephalus and short limbs. Her husband was 29-year-old, and

there was no family history of congenital malformations.

Prenatal ultrasound at 30 weeks of gestation revealed a

bipar-ietal diameter of 7.91 cm (31.89 weeks), an abdominal

circumference of 23.49 cm (27.81 weeks), a femur length of

4.88 cm (26.4 weeks), prominent forehead, micrognathia,

ambiguous external genitalia, ventriculomegaly, and corpus

callosum hypogenesis (

Fig. 1

). Other internal organs were

unremarkable. Ultrafast magnetic resonance imaging showed

ventriculomegaly and hypoplasia of the splenium of corpus

callosum (

Fig. 2

). Amniocentesis was performed at 30 weeks

of gestation, and 56 mL of amniotic fluid was aspired, of

which 20 mL was for array comparative genomic

hybridiza-tion (aCGH) using uncultured amniocytes, 20 mL for culture

and conventional cytogenetic analysis, and 12 mL for

muta-tional analysis of the FGFR3 gene. Oligonucleotide-based

aCGH of CytoChip Oligo Array (BlueGnome, Cambridge,

UK) was applied in the uncultured amniocytes. The aCGH

analysis revealed a female with a 22.2-Mb deletion of

1p32.3-p31.1 encompassing the genes of NFIA (61,103,519

e

61,694,617 bp), GPR177, and 89 additional genes. The result

was arr cgh 1p32.3p31.1 (55,500,291

e77,711,982 bp)
1,

according to CytoChip Oligo Array [UCSC genome browser

on human, March 2006 (NCBI 36/hg 18) assembly] (

Fig. 3

).

Subsequent

conventional

cytogenetic

analysis

revealed

a karyotype of 46,XX,del(1)(p31.1p32.3)dn (

Fig. 4

). The

parental karyotypes were normal. Fluorescence in situ

hybridization analysis using bacterial artificial chromosome

clone probes RP11-31P4 (61,339,876

e61,527,391 bp)

(spec-trum red) at 1p31.3 encompassing the NFIA gene and

RP11-438F14 (spectrum green) at 1q44 as internal control

showed absence of the red signal in the del(1) (p31.1p32.3)

chromosome (

Fig. 5

). The fluorescence in situ hybridization

result was consistent with haploinsufficiency of the NFIA

gene. Mutational analysis of the FGFR3 gene revealed no

mutation and thus excluded achondroplasia. At 33 weeks of

gestation, a dead fetus was delivered with a body weight of

1536 g (

<5

centile); a body length of 41 cm (

<5

centile);

relative macrocephaly; a broad face; prominent forehead;

hypertelorism; anteverted nostrils; micrognathia; low-set ears;

and ambiguous external genitalia with labial fusion, labial

hypertrophy, absence of vaginal opening, and clitoral

Fig. 4. (A) A karyotype of 46,XX,del(1)(p31.1p32.3). The arrows indicate the breakpoints. (B) Partial G-banded karyotype of the fetus shows one normal chromosome 1 and one aberrant chromosome 1 of del(1)(p31.1p32.3). del¼ deletion.

Fig. 5. Fluorescence in situ hybridization using bacterial artificial chromosome clone probes RP11-31P4 (61,339,876e61,527,391 bp) (spectrum red) at 1p31.3 encompassing the NFIA gene and RP11-438F14 (spectrum green) at 1q44 as internal control shows absence of the red signal in the del(1)(p31.1p32.3) chromosome. del¼ deletion.

hypertrophy (

Figs. 6

e8

). Polymorphic DNA marker analysis

determined a paternal origin of the deletion (

Fig. 9

) (

Table 1

).

Discussion

The de novo deletion of 22.2 Mb encompassing

1p32.3-p31.1 in the present case mainly affects the proximal region

of 1p32.3, the entire regions of 1p32.2, 1p32.1, 1p31.3, and

1p31.2, and the distal region of 1p31.1. A critical region for

hypoplastic/absent corpus callosum and ventriculomegaly

has been proposed at 1p31.3-p31.2 in a series of five patients

of chromosome 1p32-p31 deletion syndrome with

hap-loinsufficiency of the NFIA gene

[1]

.

Table 2

shows the

clin-ical findings of eight individuals, including the present case

with chromosome 1p32-p31 deletion syndrome.

Sivasankaran et al

[3]

first reported the association of

inter-stitial deletion of chromosome 1p with absent corpus callosum.

Fig. 6. Whole body view of the fetus at birth.

Fig. 7. Craniofacial appearance of the fetus at birth.

Fig. 8. Abnormal female external genitalia with labial fusion, labial hyper-trophy, clitoral hyperhyper-trophy, and absence of vaginal opening.

The baby girl had a karyotype of 46,XX,del(1)(p22p32)dn,

absent corpus callosum, ocular hypertelorism, low-set ears,

upturned nostrils, mesomelic shortening of the limbs,

hypo-plastic labia minora, and absent clitoris, and the clinical

features were similar to chromosome 1p32-p31 deletion

syndrome. Campbell et al

[4]

and Lu et al

[1]

reported two

half-siblings with a maternally inherited unbalanced

intersti-tial deletion of del(1)(p31.2p32.3) encompassing a region of

12 Mb and containing the entire NFIA gene and 47 additional

genes. Both patients exhibited ventriculomegaly or

hydro-cephalus, a thin or agenesis of the corpus callosum (ACC),

syringomelia, a tethered spinal cord, and/or left vesicoureteral

reflux. Shanske et al

[5]

and Lu et al

[1]

reported a boy with

a 12-Mb deletion of 2q14.3

/q21 involving 39 genes and

a reciprocal translocation of t(1;2)(p31.3;q22.1) involving

a 3.9-kb breakpoint between Exons 7 and 8 of the NFIA gene.

The patient exhibited hypoplastic corpus callosum,

nonpro-gressive ventriculomegaly, and a gray matter heterotopia. Lu

et al

[1]

investigated two new cases with chromosome

1p32-p31 deletion syndrome in addition to three cases previously

reported by Campbell et al

[4]

and Shanske et al

[5]

. The first

new case was a 6-year-old girl with congenital hydrocephalus,

a thin corpus callosum, Type I Chiari malformation, a tethered

spinal cord, a low vertebral deformity, congenital bilateral

dysplastic kidneys, bilateral ureterovesical reflux,

hydro-nephrosis, and a karyotype of 46,XX,t(1;20)(p31.3;q13.31)dn.

In that case, the breakpoint at 1p31.3 had disrupted Intron 2 of

the NFIA gene. The second new case presented ACC and

ventriculomegaly on second trimester ultrasound and

man-ifested additional abnormalities of a tethered spinal cord,

Type I Chiari malformation, and dysplasia of the anterior left

temporal fossa in childhood. The patient had a karyotype

of 46,XY,t(1;3)(p31.1;q25.1) del(1)(p31.3p32.1)dn with a

2.2-Mb chromosome deletion of 1p32.1-p31.3, including the

complete deletion of the NFIA gene and eight additional

genes. Koehler et al

[2]

recently reported an infant girl who

had a karyotype of 46,XX,del(1)(p31.3p32.2)dn with a 4.9-Mb

deletion of 1p32.2-p31.3. The deleted region included the

NFIA gene and 16 additional genes. The patient manifested

characteristic facial dysmorphism, a high palate, cutis

mar-morata, macrocephaly, hypotonia, and developmental delay.

Radiological examinations showed hypoplastic corpus

cal-losum, ventriculomegaly, a large retrocerebellar cyst, and

hypoplastic cerebellar vermis.

The present case had haploinsufficiency of the NFIA gene.

There are four independent NFI genes in mammals: NFIA

(OMIM 600727), NFIB (OMIM 600728), NFIC (OMIM

600729), and NFIX (OMIM 164005)

[6]

. NFI proteins act as

cellular transcription/replication factors and play a key role in

central

nervous

system

development,

including

axonal

outgrowth, and guidance as well as glial and neuronal cell

differentiation

[7]

. NFIA has been shown to be highly

expressed in heart, liver, brain, lung, ovary, skeletal muscle,

kidney, testis, pancreas, spleen, and fetal liver and brain

[8]

.

das Neves et al

[9]

found that disruption of the NFIA gene in

mice caused perinatal lethality. They also found that the rare

surviving homozygous NFIA

mice had absent corpus

cal-losum, hydrocephalus, neurological defects, male sterility, and

low female fertility. Shu et al

[10]

found altered formation of

forebrain midline glial structure and commissural projections

in NFIA knockout mice. Deneen et al

[11]

found that NFIA

regulated gliogenesis and oligodendrocyte differentiation in

developing spinal cord. Plachez et al

[12]

found that in

addi-tion to regulating the formaaddi-tion of axon guidance substrates,

NFIA has a cell-autonomous role in cortical development. Lu

et al

[1]

additionally found that NFIA haploinsufficiency can

cause central nervous system malformation and urinary tract

defects.

The present case also had haploinsufficiency of the GPR177

gene. GPR177, the mouse orthologue or Drosaphila Wntless/

Evi/Srt, is required for embryonic axis formation

[13]

.

GPR177 is a transmembrane protein pivotal to mediating the

secretion of Wnt signal proteins, which are essential for

regulating neuronal development

[14]

. Recently, Fu et al

[15]

found that loss of GPR177 in the Wnt1-expressing cells causes

abnormalities of mid/hindbrain and craniofacial defects.

Chromosome 1p32-p31 deletion with haploinsufficiency of

the NFIA gene in the present case was rapidly diagnosed

by aCGH using uncultured amniocytes obtained by late

Fig. 9. Representative electrophoretograms of quantitative fluorescent poly-merase chain reaction assays. The marker D1S1195 shows only one maternal allele (136 bp) in the fetus indicating a paternal origin of the deletion.

Table 1

Molecular results using polymorphic DNA markers specific for chromosome 1pa

Markers Father Mother Fetus Location

D1S3175 137, 137 137, 141 137, 141 1p34.1 (44,128,994e44,129,123) D1S1195 148, 148 136, 136 136 1p31.1 (71,531,646e71,531,782) D1S3471 161, 161 157, 165 157, 161 1p22.3 (84,079,923e84,080,083)

a

Alleles (base pair sizes) are listed below each individual.

amniocentesis in the third trimester. Rapid genome-wide

aneuploidy diagnosis using uncultured

amniocytes and

aCGH in pregnancy with abnormal ultrasound findings

detected in late second and third trimesters have been well

described

[16,17]

. Application of aCGH using uncultured

amniocytes obtained by amniocentesis in late gestation, as

shown in this case, is less invasive and more efficient in rapid

aneuploidy diagnosis of subtle chromosome aberrations as

well as identification of the candidate gene responsible for the

specific phenotype.

In addition to 1p32-p31 deletion, at least 17 ACC

signifi-cant critical regions, including 12 Class I regions have been

identified, such as 1p36 deletion, 1q41-q42 deletion, 1q43-q44

deletion, 4p16.1-p16.3 deletion, 6p25 deletion, 6q26-q27

deletion, 8p22-p21.3 duplication, 9q34.3 deletion, 11q25

duplication,

13q32.3-q33.1

deletion,

13q34

duplication,

14q12-q13.1 deletion, 14q32.3 deletion, 21q22.11-q22.3

duplication, 21q22.2-q22.3 deletion, Xp22.3 deletion, and

Xq27.3-q28 duplication

[18]

. In addition to NFIA at

1p31.3-p31.2, other candidate genes associated with ACC include

Table 2

Clinical findings of the reported cases with chromosome 1p32-p31 deletion syndrome

Authors Karyotype Molecular findings Clinical features Sivasankaran et al[3] 46,XX,del(1)

(p22p32)dn

NA Low birth weight (2800 g), absent corpus callosum, macrocephaly, ocular hypertelorism, low-set ears, upturned nostrils, short philtrum, high-arched palate, webbed neck, widely spaced nipples, mesomelic shortening of limbs, clinodactyly, patent ductus arteriosus, atrial septal defect, abnormal external genitalia, hypoplastic labia minora, and absent clitoris. Campbell et al[4] patient 1, same as Lu et al[1] case DGAP 205-1s 46,XX,del(1) (p31.2p32.3)mat 12-Mb deletion of 1p32.3-p31.2 containing NFIA and 47 additional genes

Low-birth weight (41 weeks, 2770 g), macrocrania, small nose, mouth and chin, narrow up-slanting palpebral fissures, ventriculomegaly, absent corpus callosum, congenital dysplasia of the hip, developmental delay, urinary incontinence, Chiari I malformation, syringomelia, and tethered spinal cord. Campbell et al[4] patient 2, same as Lu et al[1] case DGAP 205-1 46,XY,del(1) (p31.2p32.3)mat 12-Mb deletion of 1p32.3-p31.2 containing NFIA and 47 additional genes

Inguinal hernia, bilateral undescended testes, macrocephaly, right hemiplegia, mild left posterior plagiocephaly, telocanthus, hypertelorism, long flat feet, cutis marmorata, a thin corpus callosum, ventriculomegaly, decreased periventricular white matter, flattening of the frontal and parietal gyri, small nose, mouth and chin, narrow up-slanting palpebral fissures, tethered spinal cord, bilateral urinary reflux, and developmental delay. Shanske et al[5] same as Lu et al[1] case DGAP 089 46,XY,t(1;2) (p31.3;q22.1) del(2)(q14.3q21)dn 12-Mb deletion of 2q14.3-q21 involving 39 genes, and 3.9-kb breakpoint at 1p31.3 locating between Exons 7 and 8 of NFIA

Low birth weight (term 2800 g), patent ductus arteriosus, seizures, a gray matter heterotopia, ventriculomegaly, hypoplastic corpus callosum, developmental delay, relative macrocephaly, hypotelorism, hypoplastic nasal ala, hypotonia, and cryptorchidism.

Lu et al[1]

case DGAP 104

46,XX,t(1;20) (p31.3;q13.31)dn

Disruption of Intron 2 of NFIA at 1p31.3 and disruption of C20orf32 at 20q13.31

Congenital hydrocephalus, thin corpus callosum, Chiari I malformation, tethered spinal cord, and low vertebral deformity at birth. Congenital bilateral dysplastic kidneys, bilateral vesicoureteral reflux, ureterovesical junction diverticulum, hydronephrosis, and ureteral reimplantation surgery at age 2 years. Lu et al[1] case DGAP 174 46,XY,t(1;3) (p31.1;q25.1) del(1)(p31.3p32.1)dn

Disruption of NEGR1 at 1p31.1, deletion of NFIA and eight additional genes

Agenesis of the corpus callosum and ventriculomegaly on second trimester ultrasound. Additional findings after birth: tethered spinal cord, Chiari I malformation, and dysplasia of the anterior left temporal fossa.

Koehler et al[2] 46,XX,del(1) (p31.3p32.2)dn

4.9-Mb deletion of 1p32.2-p31.3 containing NFIA and 16 additional genes

Macrocpehaly, hypotonia, board face and prominent forehead, low-set ears, concave profile of the nose, anteverted nose, small chin and mouth, high palate, sparse eyebrows, cutis marmorata, hypoplastic corpus callosum, ventriculomegaly, large retrocerebellar cyst, hypoplastic cerebellar vermis, and developmental delay.

Present case 46,XX,del(1) (p31.1p32.3)dn

22.2-Mb deletion of 1p32.3-p31.1 encompassing NFIA, GPR177, and 89 additional genes

Ventriculomegaly, corpus callosum hypogenesis, macrocephaly, micrognathia, and ambiguous external genitalia on prenatal ultrasound. Low-birth weight (33 wk, 1536 g), relative macrocephaly, anteverted nostrils, micrognathia, low-set ears, labial fusion, labial hypertrophy, absence of vaginal opening, and clitoral hypertrophy at birth.

AKT3 (OMIM 611223) at 1q44

[19,20]

, DISP1 (OMIM

607502) at 1q41

[21]

, FOXG1 (OMIM 164874) at 14q13

[22

e24]

, and ZIC2 (OMIM 603073) at 13q32

[18]

.

In conclusion, prenatal diagnosis of ventriculomegaly with

an abnormal corpus callosum should alert subtle

chromo-some aberrations and prompt molecular cytogenetic

investi-gation if necessary. The present case provides evidence that

fetuses with chromosome 1p32-p31 deletion syndrome and

haploinsufficiency of the NFIA gene may present

ven-triculomegaly,

corpus

callosum

hypogenesis,

abnormal

external genitalia, and intrauterine growth restriction in the

third trimester.

Acknowledgments

This work was supported by research grants

NSC-97-2314-B-195-006-MY3 and NSC-99-2628-B-195-001-MY3 from the

National Science Council and MMH-E-100-04 from Mackay

Memorial Hospital, Taipei, Taiwan.

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