Kagami-Ogata Syndrome: Case Series and Review of Literature

Abstract

Kagami-Ogata syndrome (KOS) (OMIM #608149) is a genetic imprinting disorder affecting chromosome 14 that results in a characteristic phenotype consisting of typical facial features, skeletal abnormalities including rib abnormalities described as “coat hanger ribs,” respiratory distress, abdominal wall defects, polyhydramnios, and developmental delay. First identified by Wang et al in 1991, over 80 cases of KOS have been reported in the literature. KOS, however, continues to remain a rare and potentially underdiagnosed disorder. In this report, we describe two unrelated male infants with differing initial presentations who were both found to have the characteristic “coat hanger” rib appearance on chest X-ray, raising suspicion for KOS. Molecular testing confirmed KOS in each case. In addition to these new cases, we reviewed the existing cases reported in literature. Presence of polyhydramnios, small thorax, curved ribs, and abdominal wall defects must alert the perinatologist toward the possibility of KOS to facilitate appropriate molecular testing. The overall prognosis of KOS remains poor. Early diagnosis allows for counseling by a multidisciplinary team and enables parents to make informed decisions regarding both pregnancy management and postnatal care.

Case report: Prenatal diagnosis of Kagami–Ogata syndrome in a Chinese family

“…Most patients with KOS invariably have developmental delays and feeding difficulties. Other long-term complications may include seizure disorder and the need for tracheostomy and/or gastrostomy tubes ( Sakaria et al, 2021 ).…”

Transient Polyhydramnios during Pregnancy Complicated with Gestational Diabetes Mellitus: Case Report and Systematic Review

“…In the literature, 15 (31.91%) neonates presented an unfavorable evolution with death occurring at variable times from delivery: 3 perinatal deaths (6.38%), 5 neonatal deaths (10.64%), and 7 infant deaths (14.89%). In nine cases (19.15%), death occurred due to respiratory failure; in one case, the parents decided to discontinue the life-sustaining measurements due to very poor prognosis [ 18 ], and in one case (2.13%), the neonate was stillborn [ 19 ].…”

Prenatal Diagnosis of a Mosaic Paternal Uniparental Disomy for Chromosome 14: A Case Report of Kagami–Ogata Syndrome

“…Among 23 patients with upd(14)pat in a 2015 review by Kagami et al 22 patients needed mechanical ventilation or had feeding difficulty, and information was lacking for one patient ( 4 ). The overall prognosis of KOS remains poor; there were 23 deaths among 77 cases of KOS, including one termination of pregnancy at 21.5 wk of gestation, and the mortality rate was 29.9%, based on a review by Sakaria et al ( 7 ). Identifying KOS prenatally is very important.…”

“…In a review by Kagami et al ( 4 ), polyhydramnios was described in 32 of 34 cases; one case was probable, and only one case with deleted MEG3-DMR of maternal origin did not show polyhydramnios. Approximately 77 cases of KOS have been reported ( 7 ). Here we summarized the prenatal ultrasound findings on KOS based on the more reported cases in Table 2 .…”

“…Among all published KOS cases, more than 60% were caused by upd (14)pat, ∼25% were due to microdeletions, and ∼10% were derived from epimutations of the chromosome 14q32 imprinted region (5,6). Based on a recent KOS literature review by Sakaria et al (7), 77 cases of KOS were reported, but only one mosaic upd (14)pat had been reported in a patient with mild KOS phenotype (8). In 2007, Mattes et al reported a case but with a mosaic karyotype 47, XX, +mar (14)[44]/46,XX(6) (9).…”