Table 1.
Discordant anomalies in lateral, ventral and caudal conjunction patterns.
| Type of Twins with Discordances Retrieved from the Literature | Amount | Literature |
|---|---|---|
| Laterally united twins | ||
| Parapagus dicephalus with discordant anencephaly | 7 | [9,14,15,18,19,20,21] |
| Parapagus dicephalus with discordant cleft lip/palate | 1 | [22] |
| Parapagus dicephalus with discordant holoprosencephaly | 2 | [23,24] Figure 4D |
| Parapagus dicephalus with discordant polydactyly | 1 | [25] |
| Parapagus diprosopus with discordant synophthalmia/proboscis | 1 | [26] |
| Parapagus diprosopus with discordant cebocephaly | 1 | [25] |
| Parapagus diprosopus with discordant anophthalmia and cleft lip palate | 1 | [27] |
| Parapagus diprosopus with discordant cyclopia | 1 | [28] |
| Parapagus diprosopus with discordant cleft lip | 1 | [29] |
| Parapagus diprosopus with discordant polydactyly | 1 | [30] |
| Ventrally united twins | ||
| Thoracoileopagus with discordant cleft lip/palate | 9 | [8,13,31,32,33,34,35,36,37] |
| Thoracoileopagus with discordant scoliosis and vertebral anomalies | 1 | [38] |
| Thoracoileopagus with discordant anencephaly | 1 | [39] |
| Thoracoileopagus with multiple discordances in both twins * | 1 | [10] |
| Thoracoileopagus with multiple discordances in both twins * | 1 | [40] |
| Thoracoileopagus with discordant Treacher Collins-like features | 1 | [41] |
| Thoracoileopagus with multiple discordances * | 1 | [25] |
| Thoracoileopagus with discordant sirenomelia | 1 | [23] |
| Thoracoileopagus with discordant anal/cloacal malformations | 3 | [35,42,43] |
| Thoracoileopagus with discordant cloacal exstrophy | 1 | [25] |
| Cephalothoracoileopagus with discordant OEIS-like malformations | 7 | [3,8,25,44,45,46,47] (Figure 7) |
| Cephalothoracoileopagus with discordant polydactyly/syndactyly | 3 | [25,45,46] |
| Cephalothoracoileopagus with phenotypically discordant sex but genotypically female | 1 | [48] |
| Caudally united twins | ||
| Ileoischiopagus with discordant hydrocephaly | 1 | [49] |
| Ileoischiopagus with discordant microcephaly | 1 | [50] |
| Ileoischiopagus with discordant anencephaly | 1 | [51] |
| Ileoischiopagus with discordant meningocele | 1 | [52] |
| Ileoischiopagus with discordant cleft lip and palate | 2 | [49,50] |
| Ileoischiopagus with discordant pseudohermaphroditism, gastroschisis and anencephaly | 1 | [53] |
| Ileoischiopagus with multiple discordances * | 1 | [54] |
| Ileoischiopagus with discordant hygroma colli and Down syndrome-like features | 1 | [25] |
| Ileoischiopagus with discordant Pierre Robin syndrome-like features | 1 | [55] |
| Total found twins with discordances from literature | 58 | |
| Novel cases of Twins with Discordances Retrieved from Museal Surveys | Amount | Location |
| Laterally united twins | ||
| Parapagus dicephalus with discordant anencephaly | 2 | 1 from Berliner Medizinhistorisches Museum der Charité (Figure 4A) and 1 from Narrenturm |
| Parapagus dicephalus with discordant cleft lip/palate | 1 | Narrenturm (Figure 4B) |
| Parapagus dicephalus with discordant transverse limb defects | 1 | Narrenturm (Figure 4C) |
| Ventrally united twins | ||
| Thoracoileiopagus with discordant celft lip/palate | 3 | 2 from Narrenturm (Figure 5A,B) and 1 from Collections d’anatomie pathologique Dupuytren (Figure 5C) |
| Thoracoileiopagus with discordant sirenomelia | 1 | Narrenturm (Figure 5D) |
| Thoracoileopagus with discordant anal atresia, micromelia and polydactyly | 1 | Berliner Medizinhistorisches Museum der Charité (Figure 5E) |
| Prosopothoracoileopagus with discordant cleft lip/palate | 1 | Narrenturm (Figure 8A) |
| Cephalothoracoileopagus discordant for longitudinal limb deficiency | 1 | Collections d’anatomie pathologique Dupuytren (Figure 8B) |
| Caudally united twins | ||
| None | ||
| Total found twins with discordances from museal collections | 11 |
* See text and original reference for all details.