Prenatal Diagnosis of Pericentric Inversion in Homologues of Chromosome 9: A Decision Dilemma

ABSTRACT

Pericentric inversion of one chromosome 9 [inv(9)] is considered a polymorphic variation and is one of the most common forms of autosomal inversion diagnosed prenatally in amniocytes. Yet its clinical significance remains uncertain. Most publications suggest that this finding is insignificant. However, some articles report on abnormal ultrasonic findings in association, such as hydramnios, anhydramnios, hydroureter, hydronephrosis, encephalocele, and prune belly syndrome. Other reports suggest that inv(9) might be one of the etiologies of psychiatric disorders. The homozygote state, on the other hand, is rarely encountered. We report two cases of pericentric inversion of the two homologues of chromosome 9. Two similar cases were previously reported. One affected fetus was had intrauterine growth restriction and the other had Walker-Warburg syndrome as opposed to the normal outcome of our patients. Finally, a workup of this finding is suggested.

Pericentric inversion - chromosome 9 - homologues - prenatal diagnosis

REFERENCES

• 1 Hsu L YF, Benn P A, Tannenbaum H L, Perlis T E, Carlson A D. Chromosomal polymorphisms of 1, 9, 16, and Y in 4 major ethnic groups: a large prenatal study.  Am J Med Genet. 1987;  26 95-101
• 2 Cotter P D, Babu A, McCurdy L D, Caggana M, Willner J P, Desnick R J. Homozygosity for pericentric inversions of chromosome 9. Prenatal diagnosis of two cases.  Ann Genet. 1997;  40 222-226
• 3 Baltaci V, Ors R, Kaya M, Balci S. A case associated with Walker Warburg syndrome phenotype and homozygous pericentric inversion 9: coincidental finding or aetiological factor?.  Acta Paediatr. 1999;  88 579-583 , [comment in Acta Paediatr 2000;89:750-751]
• 4 Cheong K F, Knight L A, Tan M, Ng I S. Variants of chromosome 9 in phenotypically normal individuals.  Ann Acad Med Singapore. 1997;  26 312-314
• 5 Samonte R V, Conte R A, Ramesh K H, Verma R S. Molecular cytogenetic characterization of breakpoints involving pericentric inversions of human chromosome 9.  Hum Genet. 1996;  98 576-580 , [comment in Hum Genet 1999;105:181-184]
• 6 Hansmann I. Structural variability of human chromosome 9 in relation to its evolution.  Hum Genet. 1976;  31 247-262
• 7 Teo S H, Tan M, Knight L, Yeo S H, Ng I. Pericentric inversion 9-incidence and clinical significance.  Ann Acad Med Singapore. 1995;  24 302-304
• 8 Uehara S, Akai Y, Takeyama Y, Takabayashi T, Okamura K, Yajima A. Pericentric inversion of chromosome 9 in prenatal diagnosis and infertility.  Tohoku J Exp Med. 1992;  166 417-427
• 9 Salihu H M, Boos R, Tchuinguem G, Schmidt W. Prenatal diagnosis of translocation and a single pericentric inversion 9: the value of fetal ultrasound.  J Obstet Gynaecol. 2001;  21 474-477
• 10 Miyaoka T, Seno H, Itoga M, Ishino H. A case of small cerebral cyst and pericentric inversion of chromosome 9 that developed schizophrenia-like psychosis.  Psychiatry Clin Neurosci. 1999;  53 599-602
• 11 Nanko S, Kunugi H, Sasaki T, Fukuda R, Kawate T, Kazamatsuri H. Pericentric region of chromosome 9 is a possible candidate region for linkage study of schizophrenia.  Biol Psychiatry. 1993;  33 655-658
• 12 Kunugi H, Lee K B, Nanko S. Cytogenetic findings in 250 schizophrenics: evidence confirming an excess of the X chromosome aneuploidies and pericentric inversion of chromosome 9.  Schizophr Res. 1999;  40 43-47
• 13 Scarinci R, Anichini C, Vivarelli R, Berardi R, Pucci L, Rossaia L. Correlation of the clinical phenotype with a pericentric inversion of chromosome 9.  Boll Soc Ital Biol Sper. 1992;  68 175-181
• 14 Fuenmayor H M, Roldan-Paris L, Bermudez H. Ectodermal dysplasia in females and inversion of chromosome 9.  J Med Genet. 1981;  18 214-217
• 15 Stanojevic M, Stipoljev F, Koprcina B, Kurjak A. Oculo-auriculo-vertebral (Goldenhar) spectrum associated with pericentric inversion 9: coincidental findings or etiologic factor?.  J Craniofac Genet Dev Biol. 2000;  20 150-154
• 16 Serra A, Brahe C, Millington-Ward A et al.. Pericentric inversion of chromosome 9: prevalence in 300 Down syndrome families and molecular studies of nondisjunction.  Am J Med Genet Suppl. 1990;  7 162-168
• 17 Beltran-Valero de Bernabe D, Currier S, Steinbrecher A et al.. Mutations in the O-mannosyltransferase gene POMT1 give rise to the severe neuronal migration disorder Walker-Warburg syndrome.  Am J Hum Genet. 2002;  71 1033-1043
• 18 Zenker M, Dorr H G. A case associated with Walker Warburg syndrome phenotype and homozygous pericentric inversion 9: coincidental finding or aetiological factor?.  Acta Paediatr. 2000;  89 750-751 , [comment on Acta Paediatr 1999;88:579-583]