Table 2.

FISH and aCGH results for patients with holoprosencephaly and partial 18p deletions

Patient	Previous cytogenetic descriptions	aCGH results (chromosome 18)°	FISH results (TWSG1 - RP11-66J9, TGIF - RP11-22C6)	HPE severity	Other clinical feature s	Sex	References ◆
1	46,XY,idic(18q)	arr 18p11.32p11(108, 819- 15,370,683)x1; arr 18q11.1q23(16,78 3,849- 76,113,817)x3	ish del(18)(p11.22p11.31)(R P11-66J9−,RP11-22C6−)	Severe	Cyclopi a	M	Overhauser et al., 1995 [38]
2	46XX,del(18)(p11.1)	arr 18p11.32p11.21(3 8,826- 15,155,151)x1	ish del(18)(p11.22p11.31)(R P11-66J9−,RP11-22C6−)	Mild (normal brain)	DD, SMCI	F	Overhauser et al., 1995 [38]; Aughton et al., 1991 [65]
3	46,XX,del(18)(p11)	arr 18p11.32p11.21(1 08,151- 15,155,151)x1	ish del(18)(p11.22p11.31)(R P11-66J9−,RP11-22C6−)	Severe (alobar)	Unkno wn	F	Overhauser et al., 1995 [38]
4	45,X,dic(Y;18)(q;p11.2)	arr 18p11.32p11.21(5 9,754- 13,639,732)x1	ish del(18)(p11.22p11.31)(R P11-66J9−,RP11-22C6−)	Severe	Cyclopi a	M	Overhauser et al., 1995 [38]; Münke et al., 1988 [66]
5	46,XY,r(18)(p11.31q23 )	arr 18p11.32p11.32(5 9,813- 4,012,544)x1; arr 18q12.1(26,114,4 73-26,261,205)x1	ish 18p11.22(RP11- 66J9x2),del(18)(p11.31p 11.31)(RP11-22C6−)	Mild (normal brain)	DD, SMCI	M	Overhauser et al., 1995 [38]
6	Submicroscopic TGIF deletion	arr 18p11.32p11.31(5 9,754- 5,216,552)x1	ish 18p11.22(RP11- 66J9x2),del(18)(p11.31p 11.31)(RP11-22C6−)	Likely severe	Optic hypopl asia, cleft lip, DI, epileps y	M	Bendavid et al., 2006 [10]; Keaton et al., unpublished results [43]
7	Submicroscopic TGIF deletion	arr 18p11.31(3,184,0 26-4,960,239)x1	ish 18p11.22(RP11- 66J9x2),del(18)(p11.31p 11.31)(RP11-22C6−)	Mild (normal brain)	SMCI, absent labial frenulu m, pyrifor m apertur e stenosi s, normal develo pment	M	Keaton et al., unpublished results [43]
8	46,XX,der(18)dup(p11. 1p11.3)del(p11.3)	arr 18p11.32p11.31(4 ,316- 3,638,271)x1; arr 18p11.31p11.21(3 ,638,330- 15,155,151)x3	ish dup(18)(p11.22p11.22)( RP11- 66J9x3),del(p11.31p11.3 1)(RP11-22C6−)	Likely severe	Cleft lip/ palate, single nare, DI, epileps y	F	Bendavid et al., 2006 [10]
9	N/A	arr 18p11.32p11.22 (1,543- 9,719,894)x1; arr 18p11.22p11.21 (9,720,723- 15,391,751)x3 de novo	N/A	Mild	SMCI, pyrifor m apertur e stenosi s, epibulb ar lipoder moid, hearing loss	M	This report
10*	46,XX,der(18)t(6;18)(p 24.1;p11.21)pat	N/A	N/A	Severe	Agnathi a	F	Overhauser et al., 1995 [38]; Krassikoff and Sekhon, 1989 [51]

Fine mapping of the minimal critical region of 18p was performed for patients with 18p deletions of various sizes, using FISH and aCGH. °aCGH results are only given as they apply to 18p, and they were not replicated by an independent method, other than the FISH studies.

^◆Cytogenetic descriptions and clinical features previously published as noted; clinical features for patients 8 and 9 have not previously been reported.

^*A sample from patient 10 was not available for testing; as a surrogate, the patient’s clinically normal brother with 46,XY,t(6;18)(p24.1;p11.21) was tested; on aCGH, he had no clinically significant copy number variations on 18p, and FISH showed ish t(6;18)(RP11-22C6+, RP11-66J9+; RP11-22C6−, RP11-66J9−). DD – developmental delay; DI – diabetes insipidus; N/A – not applicable; SMCI – single maxillary central incisor.