Is Prenatal Diagnosis Necessary for Fetal Isolated Nasal Bone Absence or Hypoplasia?

Figures & data

Table 1 The Characteristics of INBA and INBH

	INBA (n=35)	INBH (n=20)
Maternal age(y)	28.06 ± 4.39	27.10 ± 4.50
Gestational age at ultrasound(w)	23.11±3.62	23.14±3.83
Gestational age at CMA(w)	24.58 ± 1.99	24.30 ± 2.18
Singleton	35	20
High risk of prenatal screening	1	0
Low risk of prenatal screening	32	19
No screening	2	1

Abbreviations: INBA, isolated nasal bone absence; INBH, isolated nasal bone hypoplasia.

Table 2 The Results of CMA Prenatal Diagnosis of INBA and INBH

	INBA (n =35)	INBH (n =20)	p
Aneuploidies, n (%)	1 (2.86%)	0 (0%)
Micro-duplication/deletion, n (%)	1 (2.86%)	3 (15.00%)
Total abnormalities, n (%)	2 (5.71%)	3 (15.00%)	0.10

Abbreviations: INBA, isolated nasal bone absence; INBH, isolated nasal bone hypoplasia.

Table 3 4 Cases with Micro-Duplication/Deletion After CMA Test

Case	MA (y)	GA (w)	Ultrasonic Diagnosis	Chromosome Region	CMA Test				Pregnancy Outcome
					Variation Section	Fragment Size	Variant Type	Classification
1	30	24.5	INBA	10q11.22	46,225,349–51,904,377	5.7Mb	Deletion	Pathogenic	ToP
2	25	26.4	INBH	1q21.1q21.2	146,586,249–147,844,778	1.3Mb	Duplication	Pathogenic	LB,2750g,37+5 weeks GA Normal newborn examination
3	27	25.5	INBH	4p16.3p16.1	1,124,732–8,721,580	7.6Mb	Deletion	Pathogenic	ToP
4	27	25	INBH	Xp22.31	6,455,151–8,127,579	1.1Mb	Duplication	VUS	LB,3140g,40+5weeks GA Normal newborn examination

Abbreviations: MA, maternal age; GA, gestational age; INBA, isolated nasal bone absence; INBH, isolated nasal bone hypoplasia; CMA, chromosomal microarray; VUS, variants of uncertain significance; ToP, termination of pregnancy; LB, live birth.

Table 4 2 Cases with Monogenic Diseases After WES

Case	MA(y)	Ultrasonic Diagnosis	WES Results	Inheritance	Disease Association
5	29	INBA	RUNX2 c.1021+1G>T chr6-45480145	AD	Cleidocranial Dysplasia
6	31	INBA	CDH4c.4819het_delG, p.V1607Sfs	AD De novo	Sifrim-Hitz-Weiss syndrome

Abbreviations: MA, maternal age; INBA, isolated nasal bone absence; AD, autosomal dominant inheritance.

Figure 1 The result of WES in case b due to parental verification.

Notes: Sequencing results for patient (C), patient's father (B), and mother (A). A heterozygous deletion (c.4819het_delG) in CDH4 was found in the fetus and was not detected in her parents.