ASTOMIA-AGNATHIA-HOLOPROSENCEPHALY ASSOCIATION

This association is a rare lethal abnormality considered to be the most severe form of the first arch syndrome.

It is due to two developmental disorders: Incomplete cleavage of prosencephaly at day 22-23 of embryonic development and absence or a defect of neural crest cell migration from the mesencephalon (including lack of development of the first branchial arch).

ULTRASOUND

1. Absent mandible (agnathia).
2. Absent buccal cavity and mouth (astomia).
3. Low set ears (under the face and almost fused together in the midline of the neck creases). Pinnae are usually well formed.
4. Hypotelorism / ± Cyclopia.
5. ± Holoprosencephaly (see in 50% of cases in one series).
6. Prominent eyes and no lids.
7. Proboscis.
8. Post axial polydactyly.
9. Other visceral malformations:
• Absent thyroid gland.
• Kidney or genitourinary tract anomalies.
• Vertebral anomalies.

HOLOPROSENCEPHALY-HYPOKINESIA SYNDROME

- MORSE SYNDROME

· X-linked inheritance.

ULTRASOUND

1. Holoprosencephaly.

2. Microcephaly.

3. Multiple contractures.

4. Decreased fetal activity.

5. IUGR.

6. Micrognathia.

7. Muscular atrophy of the lower limbs.

8. Male fetus.

9. Normal karyotype.

REFERENCES

1. Bixler D, Ward R, Gale JD. Agnathia-holoprosencephaly : a developmental field complex involving face and brain: report of three cases. J Craniofac Genet Dev Biol 1985;Suppl I:241-249.
2. Rolland M, Sarramon MF, Bloom MC. Astomia-Agnathia-Holoprosencephaly Association. Prenatal diagnosis of a new case. Prenat Diagn 1991;11:199-203.
3. Morse RP, Rawnsley E, Sargent S, Graham JM. Prenatal diagnosis of a new syndrome: holoprosencephaly with hypokinesia. Prenat Diagn 1987;7:631-638.
4. Hockey A, Crowhurst J, Cullity G. Microcephaly, holoprosencephaly, hypokinesia – a second report of a new syndrome. Prenat Diagn 1988;8:683-686.