Table 1. Cases in the Literature of Isochromosome 18q in Combination with Holoprosencephaly.

Author (Year)	Karyotype	Phenotypes Apart from Holoprosencephaly	Gravida, Parity	Maternal Age (y)
Wurster-Hill et al (1991)4	46XYi(18q)	Microcephaly, hypotelorism, hypoplastic nose, short neck, hypoplasia of radius and ulna, aplasia of first metacarpals, radial deviation of the hands, “rocker bottom” feet	G1, P0	31
Spinner et al (1991)5	46XXi(18q)	Bicornuate uterus, proboscis	G1, P0	25
Van Essen et al (1993)6	46XXi(18q)	DiGeorge anomaly, streak ovaries	G1, P0	26
Graf et al (2002)7	46XX,i(18)(q10)	Omphalocele, bilateral hypoplastic forearm with radial deviation of hands	G1, P0	21
De Pater et al (1997)8	Mosaic 46XX,inv	Hypotelorism, spina bifida	G7, P4	27
Levy-Mozziconacci et al (1996)9	46XX,-18, + dic(18)(p11,3)	Cyclopia, proboscis, radial deviation of left hand, agenesis of left thumb, aplasia of right thumb, bilateral clubfeet, multicystic kidney	G1, P0	27
Froster-Iskenius et al (1984)10*	46XX,i(18q)	Hypoplastic olfactory bulbs	G5, P2	37
Present case (2010)	46, XX,i(18)(q10)	Single umbilical artery, cyclopia with double fused eyes, proboscis, absence of corpus callosum, perimembranous ventricular septum defect, bicuspid pulmonal artery valves, malrotation of small bowel, bilateral hydronephrosis, right megaureter, bicornuate uterus	G2, P1	37

^*Froster-Iskenius et al reported a case of isochromosome 18q exhibiting olfactory bulbs as a minor manifestation of holoprosencephaly.¹⁰