Deregulated FGF and homeotic gene expression underlies cerebellar vermis hypoplasia in CHARGE syndrome
- King’s College London, United Kingdom
- University of Groningen, Netherlands
- Montefiore Medical Center, United States
- Howard Hughes Medical Institute, New York University School of Medicine, United States
- University College London Institute of Child Health, United Kingdom
Figures
Figure 1
Reduced Fgf8 expression and FGF signalling during early cerebellar development in Chd7-deficient embryos.
(A–C) In situ hybridisation for Fgf8 at E9.5 shows a Chd7 gene dosage-dependent reduction in Fgf8 expression in the mid-hindbrain isthmus organiser (IsO, arrows). Scale bar = 0.5 mm. (D) …
Figure 2
Chd7 and Fgf8 loss-of-function alleles interact to cause cerebellar vermis aplasia in the mouse.
(A–D) Wholemount views of the mouse cerebellum at P21. The cerebellar vermis is indicated by a double-headed arrow. Chd7+/− animals have normal cerebella, indistinguishable from wildtype and Fgf8+/− …
Figure 3
Chd7 loss results in Otx2 de-repression, loss of rhombomere 1 identity and reduced Fgf8 expression.
(A and B) In situ hybridisation for Otx2 in 4 somite stage (ss) embryos. Note the posterior expansion of Otx2 expression in the mutant embryo (arrow in B). (C and D) In situ hybridisation for Otx2 …
Figure 4
Association of CHD7 with Otx2 and Gbx2 regulatory regions in the mes/r1 region.
(A) Genomic map of the mouse Otx2 locus. The transcriptional start sites of Otx2.1 and Otx2.2 transcripts are indicated by arrows and exons by tan-coloured boxes. Positions on chromosome 14 …
Figure 5
Representative sagittal MRI scans of CHARGE syndrome patients.
(A) Sagittal T1 scan of patient #18 showing a normal vermis with a normal position, foramen of Magendi (asterisk) and subcerebellar cistern (SC). The orientation of the cerebellum relative to the …
Tables
Table 1
Cerebellar findings on MRI scans
| Patient | Sex; age at MRI (y;m) | Cerebellum | Suggestive neurological features* (age at last examination, y;m) | CHD7 mutation | |
|---|---|---|---|---|---|
| 1 | M (1;1) | Pronounced vermis hypoplasia with anticlockwise rotated axis, large foramen of Magendi and large subcerebellar cistern, fissure vermis | None (1;1) | nonsense | 934C>T |
| 2 | M (0;1) | Slight caudal vermis hypoplasia with slightly anticlockwise rotated axis, abnormal foliation, large foramen of Magendi, normal subcerebellar cistern | Ataxic gait (4;4) | nonsense | 7160C>A |
| 3 | M (1;0) | Slight caudal vermis hypoplasia with anticlockwise rotated axis, large foramen of Magendi, large subcerebellar cistern (Figure 5C,C’) | None (12;4) | deletion | 3202-?8994?del |
| 4 | F (0;3) | Slight caudal vermis hypoplasia, with anticlockwise rotated axis, large foramen of Magendi, normal subcerebellar cistern | None (2;2) | frameshift | 7106delT |
| 5 | M (5;7) | Pronounced vermis hypoplasia, with anticlockwise rotated axis, large foramen of Magendi and large subcerebellar cistern (Figure 5B) | None (7;10) | frameshift | 4779delT |
| 6 | M (0;1) | Slight caudal vermis hypoplasia, with anticlockwise rotated axis, large foramen of Magendi and large subcerebellar cistern | None (5;2) | frameshift | 5680_5681delAG |
| 7 | F (2;9) | Slight caudal vermis hypoplasia, with slightly anticlockwise rotated axis, large foramen of Magendi and large subcerebellar cistern | Broad gait (11;6) | missense | 3973T>G |
| 8 | M (1;8) | Large foramen of Magendi, large fourth ventricle (only on sagittal scans), normal subcerebellar cistern | None (12;2) | splice site | 5535-7G>A |
| 9 | M (2;2) | Large foramen of Magendi, large fourth ventricle (only on sagittal scans), normal subcerebellar cistern. Abnormal foliation in anterior vermis | None (6;2) | nonsense | 3173T>A |
| 10 | F (1;1) | Abnormal foliation caudal cerebellar hemispheres and tonsils, large foramen of Magendi (Figure 5D) | None (13;0) | splice site UV | 3340A>T |
| 11 | F (15;10) | Abnormal foliation in anterior vermis (Figure 5D’) | None (18;0) | splice site | 3990-1G>C |
| 12 | M (10;3) | Abnormal foliation in anterior vermis | Motor dyspraxia (16;10) | frameshift | 5564dupC |
| 13 | M (0;1) | Normal (indented cranial pons) | None (0;11) | frameshift | 1820_1821insTTGT |
| 14 | F (15;10) | Normal (large fourth ventricle) | None (20;6) | nonsense | 4015C>T |
| 15 | F (0;1) | Normal, (split caudal vermis) | None (5;9) | nonsense | 7879C>T |
| 16 | M (0;6) | Normal | Broad gait (10;6) | splice site | 2238+1 G>A |
| 17 | M (1;10) | Normal | None (6;4) | nonsense | 1480C>T |
| 18 | F (2;10) | Normal (Figure 5A) | None (17;3) | frameshift | 7769delA |
| 19 | M (1;0) | Normal | None (16;9) | nonsense | 1714C>T |
| 20 | M (6;3) | Normal | None (12;10) | splice site | 2443+5 G>C |
-
*
all children show motor delay due to vestibular defects.
Table 2
Otx2 qPCR primers
| Region | Forward | Reverse |
|---|---|---|
| #1 | AAACTCACCATAATCCTCCTGCC | TCCTCCCCTTCTCCTCTAAACAGC |
| #2 | CTGCTCTCCTCAACCTTCAGACTC | TTGCGTGCCTTACCTTACCG |
| #3 | CAACCACTCAAGTCAAGCCTATCTG | TCTTCCTCTGCCTCCCAAGTTC |
| #4 | CTGGCTGGTGGCTTCTGATT | TTAGGTATCGCCAGGTTGCC |
| #5 | ACACCAACTTGCTGAACAACA | TCCAGACTACTAATTAGGTGAAAATGA |
| #6 | GAAAACCAAAACCCAAACCACG | GAATGGAATCCTTAGCAAGCGG |
| #7 | AACAGGCTTGTGTCCGTCTACG | CGCTTTCTCAGCAAATCTCCC |
| #8 | CATTTTCTTGCCGTCCTGCC | AAAGTGTGCCTCCTGTGGTTCC |
| #9 | AAAAACACTGGGGAAGAAAGGG | AAATAAGAGTCAGAAGAGCGGTGC |
| #10 | GCTGAATCAAACATGAATGAGCC | CTGGGAGTAGACAACTGAGACA |
Table 3
Gbx2 qPCR primers
| Region | Forward (5’–3’) | Reverse (5’–3’) |
|---|---|---|
| #1 | CCCTTGGCTGGCTTTGAAAT | TCTGCCTTTTGTCCTGGAGA |
| #2 | TGAATCCATAGCTTACCCGC | AGGAACAAAGGGGGAAAGAA |
| #3 | CCAGGCTTTCATCTCTCGCA | ATAGGCCAAGCTAAGCACCC |
| #4 | GGGAATGGTGGAATGAATGGC | TGAGGAGTGTGCTGAAGGGACAAC |
| #5 | GTTGGCTGCCCTTTTCTTCA | ACCTCCATCTCCTCAGGCTA |
| #6 | TGTAAACACTCCCTTCCCCGTATC | CCACCCTAAACCGAAATGCG |
